This seems kind of silly. Sure the gameplay of AC2 makes that arc the better arc in the series, but wouldn't it make more sense to do one for AC and then AC2? Considering that first arc takes place first chronologically.
But the first "arc" is just a game. What do you want them to do, re-release it for the same systems it's already on? They could always include some of terrible spin-offs with Altair, but that probably wouldn't make people very happy. Don't expect to see them make something with the original game this generation. Unless it's a collection that includes all three numbered titles.
They could have ported the PSP game also. Combine those 2 games with this trilogy, call it a collection and make it more accessible to those who didn't have a chance to play those.
It is strange to make a "exclusive" game of games that are already at all the other plataforms ... so whatever, maybe they put a ribbon on it.