A notable leaker has suggested that a new Mario + Rabbids game is in development at Ubisoft, set to release as a Switch exclusive.
Mario + Rabbids Kingdom Battle - IGN
Mario + Rabbids Sparks of Hope Rayman DLC Announced at Ubisoft Forward - GameRevolution
Ubisoft CEO admits underperforming Mario + Rabbids sequel should have waited for next Nintendo console
Mario + Rabbids Sparks of Hope (NS)
Mario + Rabbids Sparks of Hope Shows Off a Big Boss Battle, Rayman Coming as DLC
My Nintendo Mario + Rabbids Sparks of Hope Sweepstakes - News - Nintendo Official Site
Mario + Rabbids Sparks of Hope Leaks Via the Official Nintendo Website, Launching in 2022
Mario + Rabbids Sparks of Hope review: one of the best Mario spinoffs - Polygon
Mario + Rabbids Sparks of Hope Review - The Rabbids Talk Now And They're Actually Pretty Funny - GamerBraves