I'm confused... because I see plenty of cap space.
Here's the problem.
Right now, as far as the Rangers are concerned, unless they move someone like Fox, Kakko or Shesterkin, rookie bonus money = real money. Whoever they pick #1 is going to play in the NHL and cost around 3.7M in cap hit. Not 950K in cap hit like they normally do. With that in mind, the Rangers have 22M in cap space (23M - the 1.1M from the tweet)
Assuming Lafreniere takes up an additional 3.7M, that leaves them with 18M. They still need 4 forwards, 3 defensemen, and a goalie after that. If Strome costs 5M and so does Deangelo (which is completely reasonable). That leaves then with 8 million to sign Gregoriev and 5 other players. Again, not THAT hard.
Unfortunately as a result of everything above, they can't use a lot of their entry level contracts (rookies) to fill the roster. Normally team use rookies because they're cheap. Unfortunately a lot of the Ranger rookies will count for 1.6M against the cap instead of 800-900K, making it much harder to fill out the roster.
This is making it hard to fill out the roster without moving one of DeAngelo or Strome.