If they're not awarding KKW rank, then there is zero reason for them to learn the Taegeuk forms. If they are, then it's a problem. A common problem. There are a LOT of KKW schools that do not teach the KKW curriculum, for various reasons. And I support their right to teach whatever forms and curriculum they prefer. But when you sign off on a KKW rank application, one of things you are affirming is that the person you are recommending for promotion knows the KKW curriculum for that rank and can perform it at an acceptable level. It seems to me that promoting integrity while lying on rank applications is displaying a lack of integrity.
I would say this is a gray area and not exactly black and white. Although this may be because of where I came from. I think it's more true today, that they are trying for stricter standards enforcement. But I think it's more of a political issue than a technical one. (Just like a lot of recent changes and proposed changes).
In my experience working for the military (not in the military, just working for them), you get a new officer into a position, and they have to add a new program so they can meet their performance objectives and get their next rank. It doesn't matter if we already have a program that does what they do, but we need a new one. This is my opinion on a lot of the new Kukkiwon curriculum (such as the new self-defense curriculum or the proposed competition forms). It is also probably the opinion people had regarding the Taegeuks when they were first implemented, and Masters of today are following the forms that their Masters taught them. At least, that's where my Master said his forms came from - his Master before him.
And some (I believe @skribs has said his school is one example) teach something they call Palgwae forms, but which are, in fact, something entirely different.
I wouldn't call our early Palgwe forms (1, 2, and 3) to be entirely different. Palgwe 1 in particular was very similar to the others I saw. Overall it was the same, it's just I saw about 4 or 5 different versions. Some did outside blocks instead of inside blocks, some did a back stance where others did a front stance, but the overall pattern of the form was very similar. It would be like if you and I read the same book, but had a different interpretation of the voices when reading the dialog.
By the time you get to Palgwe 6, though, they are entirely different. There might be one or two moves shared between the official and what I learned. It would be like if I were reading Harry Potter and you were reading Lord of the Rings. Yeah, they both have a wizard that everyone loves and a dark lord trying to take over, but that's about where the similarities end.
Maybe one day we can have a Zoom meeting or something and I can show you what I mean.
anybody have any idea why the palgue forms so prevalent in my neck of the woods (west Michigan US)? I've recently been trying to do group workouts with other schools near mine, within about 25 miles. It's been a lot of fun! Some really good schools, a few not so great schools, but all of them with lots of passionate participants. One thing I noticed is all of the schools we trained with that called themselves TKD except ours do the palgue series of forms. The common theme is they don't do them in any particular order (9th gup belts doing Palgue sam jang as the only form they know?) and are not even a little familiar with the Taegeuk poomsae or even the older Pyung ahn. Any idea how a collection of forms that was so short lived in Korea has become the prevalent forms in my area? I will add that many of the TKD schools didn't know any lineage beyond one generation removed from their current instructor. It's an interesting phenomenon and I can't place it.
I can't speak for your neck of the woods. I can for my experience and opinions. I always learned the Palgwe forms with a little bit of a different style to Taegeuk, a style I personally prefer. The stances were deeper and wider. We chambered slightly differently. In Palgwe, we would chamber with our off-hand in a hinge position. In Taegeuk, we would chamber by having our off-hand "point" to where the technique is going. Same with kicks. A kick in Palgwe and our hands were usually in a low hinge, where a kick in Taegeuk and our hands were clutched to our chest. Palgwe forms also tend to use more of our shoulders and bigger motions, where a Taegeuk form is more a flick from the elbow.
With that said, I'd rather not do the Palgwe forms if I opened my own school, for two different reasons.
On one hand, if I am going to do a KKW/WT school, then I would rather do the Taegeuks, so there's more interoperability between my school and others. It legitimizes the school (as
@Dirty Dog suggests). It opens up more tournament opportunities. Even if a tournament has an "Open Poomsae" category, it's probably being judged by folks familiar with the Taegeuk style, who might look at deviations from the style as bad technique instead of different.
It would make it easier for other KKW students to come in, or for my students to easily join another KKW school. I could do both, but I don't see a big enough difference between them to warrant confusing the students with two different styles.
On the other hand, if I am going to go unaffiliated, then I would rather use the Palgwe style to make my own forms, which do not contain issues I have with the Palgwe forms.
One advantage of the Taegeuks over the Palgwes is that they mostly end on the same spot (except Taegeuk 1), where in the Palgwes you typically end behind the starting line. This is true of the official ones as well, because (as I mentioned above), our Palgwe 1 is nearly identical to the others.
I also don't like sections that end in a block. You see these in both the Taegeuks and the Palgwe forms. I see it in Taegeuks 2-7 and many of the Yudanja. I also see it in (our version of) Palgwe 1, 3, 5, 7, and 8. There are also a few moves that are in our higher-level Palgwe forms that just don't fit my vision of what a form should be (such as a jumping crescent kick into a crouched position).
So in this case, I would go with something inspired by the Palgwe forms, but that fits into the rules I would place on myself for designing a form.