It's a truly good question! Well it will take some time for UK to fully leave, I'd say we should be fine for another year or two.
Even if UK decides that EU nationals require visas to study in UK, I don't think it should be a huge problem. I mean UK is full of bogus universities issuing visa recommendations left and right for as little as 1000 pounds, I don't think genuine ATOs will have any problem with this
Best thing we should do is take advantage of the weak pound and book ourselves a few courses