At first I thought it was one of the Galaxy-kin, but closer inspection made me suspicious so I snapped those screenshots and after the mission looked at the variations on the Galaxy in the ship designer. I don't think it is any of those designs. The hull for one is too short. Nor do any nacelle variants fit like the ones in the screenshot do.
Second thought was Ambassador, but the pylons are all wrong.
Yeah, it was one of the things Cryptic got from Perpetual. I think Cryptic actually made the model, you can see it flying around in the background in that old first trailer they made. I think Perpetual intended this class to represent the Enterprise-F in their game. The design isn't bad though, I wonder why they removed it.