My gut feeling right now based on what little I've kept up with the rumors:
- Switch 2 launch was delayed 3-6 months for reasons that aren't entirely clear right now.
- The planned February Direct got bifurcated. 3rd party stuff remained and they rebranded the presentation into a partner showcase because those games are coming regardless of what happens with Switch 2. First party stuff that was going to be announced/shown for the OG Switch in the February Direct moved to a combination of MAR10 Day and an April Direct.
- The expected March reveal for the Switch 2 moved to mid-June to coincide with the usual summer announcements / Summer Geoff Fest
- I could see Nintendo deciding to jump the line and do something in mid-to-late May to grease the wheels / build hype but I think that it'll be very small and more like a "This is Miyamoto. Please stay tuned." type message on Xitter
- Some OG Switch announcements that were scheduled for the annual June/summer presentation were bumped up to April Direct to fill out the presentation and provide more focus on the new hardware come June.
- I think there will be a follow-up presentation in the Fall that talks more about the Switch 2 software lineup (Switch had hardware announced in October and then initial software lineup was shown 3 months later in January).
- So I think there's a possibility of two events in June: A small presentation on Switch 2 hardware and a General Direct for OG Switch. I think there's plenty of good reasons to keep the two separate.
I'm willing to entertain a mid-May Direct in lieu of an April Direct but Nintendo has absolutely NOTHING penciled in for the April (unless you count Endless Ocean due to how the calendar looks this year). PR needs something to talk about for April, and I don't think EO is going to give them enough material to run with.
Granted, looking at past years, Nintendo having nothing to release in a given month isn't unusual. Both 2022 and 2023 had the odd month where nothing released. Or one game came incredibly early in the month.
If we're following the usual "two weeks after a major release" theory... then the earliest an April presentation could be is 4/5 since we just got Showtime and Nintendo is putting some pretty hefty marketing behind it. A May Direct would have to follow Endless Ocean and that would be 5/16 at the earliest, but they also have to balance running a Direct right before TTYD so it's going to be a tough to sandwich it in between those two games.
Regardless of if it's April or May that'll let them get the June-August calendar filled in. Waiting until early-to-mid June is too late and by that point they're going to want to be talking about Switch 2 assuming the rumored timeline is still true.
tl;dr:
General Direct in April. Switch 2 Hardware Event in June. General Direct in June for the OG Fall lineup. Usual Direct in September as has been the case since 2017 for the OG Switch. Switch 2 Software Event in September.