It is the same situation in Germany at least. If you want to get an internship after you graduated you can do it but your employer has to register you as an employee and pay taxes and at least minimum wage and everything. Most companies will therefore simply just hire students - much cheaper. I have never seen an intern here that already graduated. The idea behind that is that people with a degree shouldn’t destroy the market by interning for the next ten years of their life. Ideally people who are not ready for the market shouldn’t graduate yet anyway, in my opinion.
And on the topic: I think being a “top talent” and looking for an internship late in the season are two things that have little to do with each other. I think attracting top talent has less to do with timing and more with the prestige the company has to offer.