I've heard similar things from an individual who was up there in AOA administration. If you think about it, there's a pretty simple and logical path that this could take:
Once the merger is complete, there is no reason to have 2 separate sets of board exams. The ACGME could easily require that anyone seeking residency will be required to take USMLE which would make COMLEX completely meaningless other than to appease COCA and the AOA. However, if that happened it's likely DO schools would simply shift their focus to teaching to the USMLE instead of COMLEX, especially if USMLE pass rates were too low. I think that would eventually lead to the phasing out of COMLEX altogether. ACGME could also require applicants to take NBME shelf exams instead of NBOME shelfs, at which point there is no longer any purpose for the NBOME to exist as a licensing entity at all other than just to make money. Once all of the licensing requirements and pre-requisites between DOs and MDs for residency are the same, then the ACGME/LCME will hold all the power and could make a legitimate attempt to strong-arm the AOA into an amalgamation of the two degrees.
The biggest challenge of this would be wrestling the financial aspect away from COCA and fighting the political backlash, which if new DO schools keep opening and it leads to increased attrition, lower match rates, and lower board scores and pass rates, they'll have a pretty strong argument for a hostile takeover. To tie this back in to the actual topic of the thread, if DO schools start heading in the direction of Carib schools and have terrible 4 year graduation rates, it's just going to be more ammo for those who want integration of the two degrees. It will also likely hurt the newer schools far more than the older ones which have the experience and resources available to manage a change like that.
The other reason I think this could feasibly happen is that, imo, the AOA does not have the same level of support from the younger generation of DOs than it does from the old guard. Most of the younger generation either doesn't believe in OMM or is at least skeptical of many of the techniques. Even more of us just can't stand the AOA and many of the hoops that we have to jump through and still have a bias held against us. So when the time comes and that AOA starts looking for help from their own, I don't think they're going to get the level of support that they'll need.
Of course, this is all complete speculation and there's a chance that none of this will happen. Personally, I wouldn't mind if the DO degree and schools were absorbed into the MD world, as there are too many other issues facing physicians today and on the horizon for us to be fighting with each other. So the sooner this all gets figured out the better imo, but I'm also sure this would not be a smooth transition and that there will be a fight as there has been in the past with issues like the merger.