Drafting in the NHL is always about selecting the best player available; these players are usually multiple years away from making the league, and that’s if you’re lucky.
That said, the Leafs genuinely lack centers in their system. Last year, they drafted three times, and none were centers. In the two drafts before that, they drafted two centers of note: Roni Hirvonen and Mikhail Abramaov. Abramov had a decent enough rookie year with the Marlies but nothing that leaps off the page. There are a few other young centers on the Marlies with potential in Alex Steeves (who I’d suggest projects better as a winger at the NHL level) and Curtis Douglas.