When I think about it, Duggan getting two X-Books makes some amount of sense to me.
Gerry Duggan always writes 3 books for Marvel at any one time. I think it's baked into his pay rate.
In late 2020, he had Marauders / Cable / Savage Avengers.
When Cable came to an end in July 2021, he had X-Men / Marauders / Savage Avengers.
When Marauders comes to an end this month, he'll have X-Men / Devil's Reign: X-Men / Savage Avengers.
Devil's Reign: X-Men and Savage Avengers both end by March 2022, leaving only X-Men.
So it makes sense to me that he'll get two more Marvel books in Spring 2022 - one X-book and one non-X-book.
Whether X-Men Red is the X-book he is getting - well, he recently wrote X-Men Green in the Unlimited format (and even hinted that there will be more X-Men Green next year), which at the very least shows that he likes the X-Men (colour) format of books.
If X-Men Red isn't the Mars book, then I can definitely see it being the expansion book for Gerry Duggan's X-Men.
Regarding Benjamin Percy, he writes about 2 books for Marvel (+ a bunch of indie minis and a TV show he's working on which keeps him busy).
He has a Ghost Rider ongoing launching next year.
I think that it's a bit unlikely that he will be doing both X-Force and Wolverine in the relaunch, especially when he'll be coming off a 10-week weekly event.
bishop66 says that he will be doing only one of those, and between the two I think that it is more likely that he sticks to the Wolverine solo and someone else gets X-Force. But I'm not sure.