We don't know who is developing DK yet, so if it's not the 3D Mario team, I can still see 3D Mario coming out in October/November (maybe do ZA for October and 3D Mario in November, which would be a nice 2013 callback....especially if GTA VI is still on track for 2025 lol).
It's been so long since the last 3D Mario game, so even if DK is made by them, I could still see 3D Mario coming for the holidays (if DK was a holiday title, I'd say that 3D Mario wouldn't happen this year). We did get Pikmin 3 & Mario Wonder in the same year, and I'm pretty sure there was overlap with the team. 8 years after Odyssey, and all they'd have is Balloon World, Bowser's Fury (which had assistance from other studios) & DK?
It's entirely possible that they weren't even working on DK anyways. When Peach Showtime was announced, people thought the 3D Mario team did it, but it turns out that it was Good-Feel.
Either way, I do think at least 1 more big Switch 2 exclusive will be announced before the end of the year for release during the holidays. They'd also announce at least one or two 2026 titles. Could see a Direct happening in July or August (and then another Pokemon Presents in August like recent years besides 2024). 3D Mario (or Mario in general) could get a dedicated Direct in September for the 40th anniversary).
Prime 4 could be Aug/Sep, ZA in Oct, 3D Mario in Nov with Air Riders & HW supplementing the first holiday. We'd then be back to our usual Feb-Jun-Sep Directs in 2026.