So you are making a moral judgment on her choice? Because you think she should view moving in with boyfriend more seriously? Possibly only doing so if they're building up to getting married?
That's nothing to do with the money and everything to do with you trying to control how she lives her life!
Removing that element
It's not going to cost you any more than you would have given her anyway.
She'll likely have a calm stable home life which can only be conducive to doing well at uni
If you push your point of view you risk pushing her away, and not just while she's at uni but tainting your relationship with her forever, you also risk offending a potential future son in law.
Potentially you're making her stay in a situation less supportive of doing well at uni.
First time I was at uni I was in standard student houseshare. It was a total pita with noise, mess, arguments about stolen food, state of bathroom etc made it really hard to get my he's down and study when the other students seemed to me more focused on partying!
Second time I was a single mum so in a normal house just with dd. Even though dd was young and it wasn't "easy" it was much better being able to get peace and space to study once dd was in bed.
Op be honest, is your real objection you think she's too young/irresponsible to move in with a romantic partner? That she's doing so too lightly for your opinion?
As ever, it seems to me it's not really about the money.