Based purely on speculation, I believe many former AOA programs will continue to have DO residents make up at least 85% of their residents. To them, they have been training DOs for years, and suddenly they think bringing in MDs will somehow validate their programs? I also believe, again on speculation, that for every MD that takes up a DO spot in an AOA residency, that a DO will take a spot in a MD residency (maybe not the same specialty of course, but that point is that I think with the merger that many more ACGME PDs will be more comfortable at ranking and considering DOs then say 5 years ago).
Ultimately, I think the overall effect will be small to moderate in the grand scheme of things. I trust that the AOA and AOA PDs are rational decision makers and stakeholders, and want to continue offering DOs as much of a chance at certain specialties. Time will tell--until then I think frequent speculation is an act of futility to be frank. Let the process play out, but certainly let our voices be heard through SOMA and other avenues.