Originally Posted by psylockolussus
Well that sounds really smart and creative. They just didn't create the First Class movie to show things that happened in the past but to also eventually connect it to the original cast.
to me Singer came back to Fox with the FC script because he wanted to have at least one final movie with his cast, since he didnt had the chance back in 2006, but since Fox wanted other thing around 2009, he came with the idea of the prequel set in the 60's, to develop some of the characters he worked with and to connect it later to DOFP and finally do X4 right after.
Seems like a long/risky plan, I know, and probably some fans wont think this way, but if this is really the case, yeah, its a smart plan.
FC expanded the x-men universe, and now Fox has the chance to keep expanding it with any of the two casts or both.