To me, 'timed with the release' means 'at or around the same time'. If the Celebration is scheduled before the release of the movie, I'm sure they would have said something like 'immediately preceeding' or 'leading up to' instead.

Both movies will be huge blockbusters and will be showing for several weeks. With Avengers 2 scheduled for May 2015, a slight overlap is inevitable.

But if they release Ep VII in April, at least it will be on its own for a few weeks before the A2 release.

Edit: Just checked the dates. A2 is out on May 1. If Ep VII comes out on April 17, it will have a 2 week head start. Still seems quite close to me, but it's got to be better than having both out in the same month.