BioWare has to revisit this ending in some way. If the next ME game is a sequel, then the ending needs to be addressed. Ignoring it would be an insult to all the fan speculation. I think BioWare should take this opportunity to, once again, clarify their intentions with the ending, and perhaps even retcon certain things.
If the ending is a sequel, then their original intent is already sort of a moot point. Casey Hudson said that they definitely wouldn't do a Mass Effect after 3 when 3 was released.
I have no doubt they will retcon certain things. Synthesis hasn't happened or is different than as presented in ME3: the krogan wasn't glowing green in that teaser.
My guess? It's a few hundred years in the future. The relays are back, the geth are gone (unexplained, so that they could have simply left to do their own thing, not necessarily destroyed), the Reapers are gone (and you don't mention Shepard and the Reapers except in the vaguest terms, ie "Shepard ended the Reaper threat") the quarians are there, the genophage is cured.
In other words, Destroy in all but name. Synthesis was never going to work as a mid-point in an ongoing story, so if its a sequel that fate is sealed. Control will have to compromise that the Reapers left after helping rebuild, at some point.
So the Destroyers will be happy, and really they are the ones BioWare needs to appease anyway. Such a setup combined with Mass Effect 4 being a good game and gamers will be flocking back, if indeed they ever left to begin with.