Why, with Jones and Elliot about?
25 is about right. Immediate impact, loads of years left in him. Better than the likes of Camavinga, Gravenberch, Auoar etc who are often linked.
To @redfanman’s point above, I don’t think Bissouma would only be a back up to Fab, he could play as an ‘8’ as well, similar to the role Keita has started in.