Personally I don't see how anyone person or group could be the sole inheritors of Gm Remy's system of Modern Arnis. GM Remy made his living on the road teaching at different seminars to different groups of people, generally martial artists in different arts. He promoted Modern Arnis to be the "art within your art" so he taught differently to different groups.
Having attended several camps/seminars with various instructors in Modern Arnis, i.e. the Motts, Dan Anderson, Bram, Datu Dieter, Datu Hartman, Jeff Delaney, Remy Jr., Datu Kelly Worden, and seeing other instructors from the PI (Bambit, Gm Tongas) at these camps and such. Generally they all teach different and have different skills, and different points of view on Modern Arnis and they all learned and trained with the same guy. All of these individuals (and many more) spent years, months, days and hours training and learning from GM Remy, but they are all very different in their approaches to the art, their presentations, etc. etc.
I don't believe it would be this diverse if he taught from a central school or location and everyone trained there and then spread out and promoted the art. While he was teaching Modern Arnis, he promoted it as the "art within your art" therefore I believe that people would come away from training camps and seminars with different views because they filtered it through their primary arts. Another reason I think the art is as diverse as is is was because the Professor taught from the view point of motion application which would lead to a even wider view instead of it being just this technique or that. Then you have him teaching some things over here in the states like the empty hand anyos and then not teaching them in other areas and so on. I remember being at my first camp and GM Remy telling my training partner (who was an instructor in Preying Mantis gung fu) that his anyo Isa was very good when he did it as if he was doing a mantis form.
With a teaching methodology like the Professor had, his life style, even his art it self, I don't see how any one person could claim to be the sole inheritor of the system. And to be honest I don't think the Professor wanted a sole inheritor, rather I do believe he would be quite proud of the way things have turned out. Maybe it is not quite what he envisioned but none the less to see the vast differences between his top students and where they have taken his art, I can help but believe he would be proud.
Another positive thing to have come out in recent years has been the seminars where the seniors are getting together and teaching; the symposium, Dan's Summer camp in 2005, Dieter Summer camps, and last years Reunion Camp hosted by Datu Hartman each one has gotten better and I believe the best is yet to come as differences are put aside. In my opinion the instruction at the camps has gotten better since GM Remy's passing and frankly the art itself has become stronger with the diversification of the teaching.