Oda isn’t done with Kidd yet, no way. One Piece 912 Spoiler, Plus he already crossed Big Mom before too by robbing one of her ships. I see where this arc is going. And remember the last time Luffy, Law and Kidd fought together.
I think Basil is with Kaidou because the tarot cards told him it was the most beneficial place to be right now. As far as Drake? I think he’s still working for the marines but undercover, sorta like I think Aokiji is secretly undercover with Blackbeard. I’m willing to bed that two things happen. 1. Luffy and co meet up with all of the supernovae throughout his travels in the new world and 2. They all end up being part of the strawhats grand fleet! In charge of a division like Whitebeard has his crew setup. Knowing Luffy it will probably be setup without his consent or concern, but allies none the less, at least allies.