Saying such and such is a principle of movement and has several applications is still dealing in 1:1 applications, just several instead of one. Abstract is merely an idea, not a physical existence taken literally into fighting. WSL's forms are abstract.
You will see footage of WSL teaching more mainstream ideas to give people a basic picture. It's very difficult to teach in a couple hours to people of various backgrounds things which need to be trained and reinforced over a long period of time. For that same reason, some of his now internationally "famous" students also only received this kind of thinking, because they were seminar attendees and/or irregular visitors to his school. He taught them simple ideas to take back in their practice. They also came with previous knowledge and didn't have the time to rebuild their understanding of the system properly.
In the DVDs previously mentioned it's all application-based and is not the correct thinking. In that DVD on SNT, three alternative interpretations are given for the last three actions before the final punches, all literal, sometimes ambiguous and make very little sense as an explanation of the action, and not a single one of them touch upon the abstract. The action really has to do with the elbows, man-sau and wu-sau, and x-ing lines.
WSL was once teaching a seminar showing these kinds of application ideas at another famous master's school. His seminar assistant said this is not what you teach me. WSL said he couldn't embarrass his friend, but later came back and told the assistant that he could teach it. The assistant began sharing the abstract thinking with the students, and the next day a group of them came and asked WSL and him to teach them.