Tali and Ashley showed up in my ending. I romanced Tali so that makes sense according to Eric's explanation. I took Tali and Ashley on every mission in the first third or so of the game, but then I switched to Tali and Garrus on every mission for more than the last half. I also missed the shot in the Garrus "bromance" scene. I'm pretty sure that Eric is right anyway, but I did find it odd that Ashley was the one instead of Garrus. If anyone were to replace Garrus though, Ashley does make the most sense in my case so yea, Eric is probably right. For EDI, she should show up as long as you didn't pick the destroy ending. I'm not sure why she didn't appear in yours because you picked the Synthesis one.