Definitely don't think we're getting Mario Maker 3 this year. Mario Wonder was finished only 3 years ago, and Nintendo needed 4 years to pump out Mario Maker 2 (which wasn't a major upgrade on the original). Nintendo is likely taking their sweet time with it. Just gotta be patient... Nintendo is not a developer known to rush projects. Mario Wonder was entirely void of deadlines, after all.

Well, we now know that Splatoon Raiders is coming about two thirds of the way through July, but haven't heard of anything else new from Nintendo.

I believe the Mario Maker team and the Mario Wonder team are largely different groups of people even though it's EPD Group 10 (Tezuka oversees both groups), so one doesn't necessarily count the other out, though I think even if it was the exact same people working on both they could probably easily make a new Mario Maker game in 3 years time. The previous two games already give them a wealth of features to quickly port into the new game and then you just have to build up from there and work in the Switch 2's mouse-con controls, which should be easy enough. 

It would also follow the same pattern as the first Mario movie in April 2023, and then a new Mario platformer (Wonder) in fall. Well this time they weren't able to get a new 2D or 3D game done for 2026, but a Mario Maker game would be the next best thing and probably a lot easier to make. 

2027 will likely be the year for the new 3D Mario platformer, so not sure if they want to also have a Mario Maker in that year, if you push it further out that gets you to 2028 ... but that's 9 years from Mario Maker 2, that's quite a huge and probably too long of a gap. 

I mean to me it would make a lot of sense, but we'll see if it pans out or not. There is a leaker who's saying Mario Maker 3 is coming this year for Switch 2 but how reliable that is, who knows.