I don't think team-ups are the concern of older decks right now.

Also I don't think that changing older team-ups to actually have the word team-up would be fair, as other cards would also have to be errata'd to please other players. Like for instance put mutant traits on older X-Men and Brotherhood characters.

I think Origins is strong enough to survive without it's team-ups and that it should worry more for Rush-Agressive decks.

Putting an errata on older team-ups won't make players want mutant traits on old characters, the situations are completely different.

Mutant traits on old characters is potentially quite nasty, but team-ups are team-ups.

I think they should be changed, or reprinted, but also, I doubt UDE are actually going to do this, which is a pity, since I'd much rather run Mutant Nation than the new team-ups for X-Men and the Brotherhood.

Not that the old cards are completely useless, but it would make sense to make them compatible with, say, Teamwork.

I think they should leave it like it is. If Midnight Sons had the team-up it could cause problems with all the search for them.

exactly, having the team-up version is part of the balance of newer teamups.

Letting certain old teamups be easily searchable, or in the case of midnight sons, MORE easily searchable, would tear a rift in the space time continuem, ripping us all a new one.