It looks like season 42 has the green light. According to spoiler account Gamer, the next Challenge season is slated to film in February and last just seven weeks.

Keep in mind, this is just an anticipated plan. Production changes things all the time, so if filming dates move, it doesn’t mean Gamer was wrong. More likely, it means producers moved the dates. As of now, if I had to guess, I’d assume the February filming schedule is a result of early availability calls.
This is a noticeably shorter filming window than other recent seasons (especially the ones that have filmed since the pandemic, starting with Double Agents), but that’s likely a good thing. Many of the veterans don’t want to spend 3 months filming a season, so the shorter window will likely entice a few people to make returns to the show.
Gamer has also stated that random rookies are getting availability calls, specifically naming Genevieve Shawcross from Love Island 3. He also stated that many random one-time Challengers from all installments of the show are getting contacted.
Likely, more information about this season will be made available in the coming weeks. Keep in mind, this information is NOT for All Stars 6. While the fate of the All Stars franchise is unclear, Gamer specifically said season 42 will be filming before the next All Stars (if it even happens).
