I got excited when I read your question. Stanford currently has 15 players on scholarship, which is the NCAA limit. They have NLI's from 3 HS seniors. Unfortunately, they graduate 4 seniors. So, yes they have room for one more scholarship on next year's team.
As good as Jones is, 15 players on the team will still impact individual coaching time and PT. Note that one of Stanford's incoming recruits is talented 6"1" Fran Belibi from CO, #23 on Hoopgurlz. Jones is better of course, but she will still have to battle for minutes against another talented wing in her own class if she heads to Stanford, not to mention the 11 returning players from this years team.
As for UConn, while I would be reluctant to say this about most incoming freshmen, I would be surprised if Haley did not crack UConn's starting lineup from Day 1 next season.