I've still never played p2. I still know about the existence of them in it, but I don't know the context, so it's fine to me. If anything, that kind of revelation that they're in it could get fans who fell in love with the series based on 3 and 4 to go back and give 2 a try. /shrug
For me, it was persona 4 arena's story, and then the speculation about prior casts. Then that led to finding out that about p2, which made me buy IS on PSN immediately.
Still, better safe than sorry I guess, even if a pic was floated around a few a days ago and is someone's avatar now.
*goes back to Beginner P1 run* Dammit, I will finish these things this month if it kills me.