Between the $7.25M & roughly $8M that Hintz will make next offseason, that's a little over $15M of the Stars projected $22.5M in cap space next offseason. That leaves the Stars a little over $7M to fill 8 roster spots, which is basically impossible unless you run with a team of primarily AHL players.

Unless the Stars make some pretty unrealistic moves, they do not have the cap space to sign Kane AND Hintz while still icing a competitive team for the 2023-2024 season.

CF shows $33.3M available with 11 spots taken.
I can't see Hintz getting more than $7M and by next year we should see Bourque, Johnston, Dellandrea and possibly Stankoven making the line up and each is less than $900K.
That leaves you with about $15.3M left to fill between 5-7 spots. This is also based on the cap only increasing by $1M and I believe that to be conservative.

I don't think the cap should be an issue in 23/24 and if there is a chance to have Kane in the line-up while he's still a point+/game player then I think it could really help this team be a serious contender.

Under the “Long Term Outlook” tab, if you scroll to the bottom it’ll show $22.6M in projected salary cap space with the roster you have created above & 13 roster spots accounted for. This is prior to any Hintz or Kane signing.

Hintz is nearly a PPG center who has turned into one of the best two-way centers in the game. A young, 70+ point center, with a borderline elite defensive game (and arbitration rights) will absolutely go for $8M a year on his next contract.