I think it seems more likely that the Horner-Newey relationship going cold has caused this.
There was that interview with Horner in February where he was playing down newey's influence and saying that he didn't do much on the rb19 and rb20. And that more credit should go to Balbo and Waché. While it may be true and the other technical heads of RB go unsung, it felt strange given how instrumental Newey has been for the team. It just felt like the knives were out.
In my opinion, Horner wanted to manoeuvre Newey out of power, just like he tried to do with Marko. Verstappen played the trump card when it came to Marko so Horner had to back down there.
Maybe he goes to Ferrari, but I don't think that's a foregone conclusion.
As for technical structure within RB, there is now scope to promote both Waché and Balbo to CTO/TD respectively both of whom Ferrari have desperately been trying to poach. Maybe this was the grand scheme for Horner.
It's shameful he's willing to damage the team so much to consolidate power.