According to our DA director, the new league will be called something like "MLS Academy" and while the details are still being worked out, it will mostly work like the DA did minus about 20% of the clubs that jumped to ECNL. They are adding Phx Rising at all levels, Liverpool in OC and some other clubs.
What will likely be different is that the u19 level might go away because MLS clubs feel that if you aren't ready to be signed by then it won't be worth their time. What teams like LAUFA, TFA, Nomads, etc will do with that age group remains to be seen. Beyond that they are getting rid of the gap year, likely getting rid of the sub rules. Not much else will change. Our DOC said MLS clubs have to do this because otherwise they couldn't afford their academies since they'd have to fly to almost every game.
Our DOC is full of shit in general, but if you liked the DA, it sounds like it will still be the DA. The downside of course is that losing the six clubs in southern CA means that there will be more out of state travel to Arizona since there will be at least three clubs there (Barca, Rising, RSLAZ). It will be interesting to see if those clubs that left try to get back in or stick with ECNL.
They said MLS is meeting today about it and final details will be available in the next couple of weeks. Basically MLS is going to do everything US Soccer resisted doing that the wanted to do. I still maintain southern CA clubs should have an alliance to play each other and limit the travel (why play Rising three times when you can play Strikers three times and not pay for a hotel, miss school, etc) but that would require DOC's to think about the best interests of the kids first.