Most Helpful Girl
Of course it's not ok, that's very selfish and disrespectful. Especially considering that she "might" change her mind.
"Hey so I won't be able to have a relationship for two years. Can you wait for me for those two years? Like there's a chance that I won't like you anymore but like... can you? It's literally a waste of time and feelings but I think I'm like totally entitled to it."
Yep. Selfish and rude. If you can't be with him now then he's better off finding someone else. You can't demand that someone is committed to you even though you have no interest in a relationship. That would make you an egoist.