This caught me a little by surprise in the sense that I wasn't expecting announcements but it's no shock that it's happening. All the big drivers want to be the number 1 driver, not equals. Vettel had the same problem with Verstappen at Red Bull and Hamilton had that problem with Rosberg at Mercedes. Leclerc is the future of Ferrari, they were never going to leave him sitting as Vettel's wing man after last year's performances.
It looks like Sainz is the odds on choice, though it says a lot about where Ferrari are. A couple of years ago, most people would have been convinced that they would have been able to entice Hamilton or Verstappen to join them, but both seem content with their teams ahead of the regulation changes next year. That's nothing against Sainz mind, who is probably overdue a shot in a competitive car.
George Russell getting Sainz' McLaren seat would be perfect for me, teaming him up with Lando Norris gives McLaren that extra bit of British interest and creates an exciting young rivalry.