It's a "Re- announcement" - "re-boot" of something worked out at least a year, or close to 2 years, ago.
A very good idea - it brings more 'buying power' to both brands, and sharing of facilities / production capacities.
I hope it works out for both of them. On the scale of things, with both Beta and Sherco bringing out their 2t Enduro bikes - together with both companies 4t Enduro offerings - we at least have not gone too far backwards, with the loss of 'Berg / Italian Huskies. Further development of the Ossa EFI 2t rearward sloper, into the Enduro bike, might be more likely with this. Ossa have been flat out with just their Trials usage of it. Of course, that 'flat out', is in the context of a tiny, (re) start up company. They are doing well, at a very small scale.
Purely from my wanting to always see something different, I'd like to see the sidevalve Gas Gas 350 4t appear:


Well, I'd like to see Gas Gas's own, more conventional 4t engines re-appear. There are some 'noises about that happening. Success of the 'partnering up', is probably key to that happening. The Electric bike(s) is something that I think Gas Gas really could further - trials usage being quite the niche E bikes can fit into, as a starter point for such a relatively small company moving further into that tech.