This makes too much sense to fall apart. It really needs to happen, IMO, for a spring league to continue to survive.
They might not keep 16 teams, but I feel like it's not impossible to do, given that the two leagues already are filling 16 rosters a season, and there is only one city's worth of overlap between the two. Move one of the Houston franchises to somewhere else in the central South or West, and you have fairly logical structures available.
For the time being, using only the teams that exist with one of the Houston teams moved, you could run something like:
Philadelphia/Pittsburgh/New Jersey/DC
Michigan/St. Louis/Memphis/New Orleans
Orlando/Birmingham/Houston/Arlington
Seattle/Vegas/San Antonio/relocated Houston (Salt Lake City, Omaha, something like that)
(I also have thoughts for a 20-team league following expansion, subtracting Houston 2 and adding Tulsa, Omaha, Portland, San Diego, and SLC:
Pittsburgh/Philadelphia/New Jersey/Michigan/DC
Orlando/Birmingham/New Orleans/St. Louis/Memphis
Houston/Tulsa/Arlington/San Antonio/Omaha
Salt Lake City/Seattle/Portland/San Diego/Vegas)
Ultimately, I just want there to be one strong, successful league, with a Philly team in it that actually plays in Philly so I can watch the games.