Africa doesn't deserve five slots, but as South Africa is automatic they'll get four in addition I think.
Asia and CONCACAF should lose one each.
But I'm not sure FIFA wants to have even more European teams than they already do. And Oceania I think is going away, as they will be folded into Asia. I think maybe what they should do is 3 and 4 CONCACAF should have a playoff with the 5 and 6 South American teams to decide who goes.