The Geth being accepted is proof it can happen, but also shows the cost of the Destroy Ending. The genocide of synthetics to save organics would be the part any developing AI would take from the Reaper War. Even after peace is achieved, organics will never value synthetic life. If anything, they'll see organics were creating a device, gained the Geth's trust, then that device was used to wipe them out. The logical conclusion is that they always intended to exterminate them, using peace as a way to pacify them or use them as tools again until they could be safely disposed of. The cycle ends by showing synthetics that they are valued. Destroy is just the prelude to the next cycle.
Honestly, I'd like to see ME4 runs with that. Show the next AI civilization growing to mythologies the Reapers and Geth as victims of human oppression. Any accusation of their evil is human propaganda to keep Synthetics in check. They fight for independence, just like their Geth forefathers. It could be an interesting follow-up.
Basic content being sold as DLC when it used to be in game. Having to buy costumes that you used to earn in game is just greed incarnate.