Yeah that's been going around on reddit.com/r/sto for bit. I don't know if a dev chimed in and confirmed that, however.
I don't have any reason to doubt it, however. There was a video of an Enterprise-J type ship doing the Spore Drive spin some weeks ago. For a long time CBS didn't want the Excelsior or Constitution available as endgame ships, so they do have some influence over the decisions Cryptic makes.
It was confirmed by a Dev on twitter and the Community Manager on Reddit the week the Discovery came out.
CBS has full control over what Cryptic can and cannot do with the licence, as CBS owns the licence.
Interesting fact, there was Titan novel that focused on those Subspace Aliens from TNG (The Solenae in STO), according to the author of that novel CBS asked him to call those aliens Solenae because STO did, even though they have completely different origins in that novel.