I don't really consider that a major spoiler since it's been public for a while that Jack is with Crimson. Just because the profile and game content don't match, it doesn't mean he's lying per se! There are just pieces to the story you don't have.
For me, it's sort of like Magnus or Caissa giving Morgan a fake name. The player knows it's fake. The player knows Caissa isn't being nice - he's trying to get Morgan in his car so he can kidnap her. Magnus is just lying through his teeth about who he is.
But that's not a big spoiler or reveal. And neither is Jack being with Crimson. The player still doesn't have the full story even if they know he's not being 100% transparent with Morgan right now.
In game play time, if Morgan goes with Jack, the full story gets revealed like...five minutes after the restaurant scene.
Thanks for taking the time to comment! <3