If it's a 2024 product, then I think a Feb/March unveiling followed by launch in June-August.
If the software is running late and they have to push into like November 2024, then I'd say a late March/April reveal.
Why do you think it would launch June-August? It’s either November 2024 or delayed to Q1 2025 because of software.
Personally I'd say best options are:
June (when kids are getting out of school)
September (allowing them to have a launch period and then a separate holiday period)
November (the typical holiday launch time)
Of those I think typical holiday launch time of November is actually the worst. Next year I'll be looking for either a reveal around February and release around June, or a reveal around May and launch around September.
And considering it's been many years since the last 3D Mario and Mario Kart, and those are the two obvious launch titles, ya gotta figure they will have those two titles ready no matter when they launch next year so I don't think concerns about software being ready would change their launch date within 2024.
If they launch June-ish have 3D Mario on launch day, Mario Kart maybe a month later (or maybe launch day also), have another big game for later summer or early fall, and one more big game for the holidays.
If they launch September-ish have 3D Mario on launch day, Mario Kart maybe a month later, and another big game another month later as the holiday game, or maybe Mario Kart is the holiday game.
If they launch during the holidays, then just have 3D Mario and Mario Kart at launch.