To be fair, ME3's ending was doomed before that game started.

I'd place it around the start of ME2.

At least you can pick the color filter to apply to the ending.

The studio's biggest sin came before that when they used DLC to paywall off major parts of the story in ME2. Anyone who didn't fork over even more of their cash got an incomplete game and a plot that made no sense.

they could go from infamously bad ending to one of most creative endings ever by just saying indoctrination theory is correct

Meh I liked it. In fact they shouldn’t have caved and added to it IMO.