No I don't think that's likely, but I still don't see why the other reasons conveniently have their own project and ships that are exactly like the human ones either. That doesn't make any sense. The only government who really believed in the reapers was the humans. If we are leaving before the reapers show up it seems pretty unlikely the other races would be part of this colonization project. Someone HAS to be leading it. Otherwise you would have all the races bickering and fighting with each other and I doubt they would have chosen humanity. That would be stupid and not believable given their distrust of humans in general. So the whole thing doesn't really sound plausible anyhow.
A small population of a species is capable of reviving an entire population especially if you consider alternatives like frozen embryos or stasis clutches for Salarians.
Say what? The Alliance government didn't believe that the Reapers were coming. Most of the top politicians in the Alliance feasted on Shepard's words after his 'death', and things didn't changed after. As far as we know the only top Alliance members believing Shepard were Hackett and Anderson. If the Alliance really believed the Reapers were coming, they'd have done a better job preparing for their arrival.
Also, as we find out in Citadel the Council did believe the Reapers were real.
Even if revival was possible in the way you mentioned ,why would other species decide to follow through this? And again ,the leak mentioned already that the krogans have their own colony ship.
I'm sorry, but I don't see how your theory is in any way possible. We'll have to agree to disagree. Though I have to thank you, since your post makes me prepared about this scenario happening.