Several creatives from the Chrono series are involved with Another Eden, so it could very well just be a nostalgia grab. The announcement from the AE team specifically says they’ll be announcing a crossover on the 4th, which appears to debunk that they’ll be announcing a Chrono Cross game release.

The Mitsuda picture could be them recording some Cross music for Another Eden. I assume the crossover will feature some tracks from CC, and I assume they would record new versions of the old songs.

I’m cautiously optimistic, but the evidence is still very thin. All of the new information points very clearly to an AE crossover, not a new Chrono Cross standalone announcement.