Thanks to several tweets from those lucky enough to get their hands on the new collection (via VCG), we've learnt that the button toys contain real Nintendo spare parts which can be used for real controller repairs. Oof.
As highlighted on Twitter by @doben_ssb, the GameCube face buttons and C-stick appear to be identical to the ones used in the OG controller, meaning that they can be swapped out and replaced (if you know how). The same applies to the N64 model, according to @Kemtex_Ninja.
So yes, this means that if your OG N64 stick is broken (and we know it likely is), Nintendo is offering an official replacement... kinda. It also means we finally have replacement GameCube parts actually made by Nintendo — albeit only available from a gacha machine in select Japanese locations.
Then again, it hardly seems to be straightforward. Twitter user @mizure3213 claims that only select parts of the toys are viable stand-ins (the C-stick 'dome', for example) while the bases would require some work to turn them into a functioning replacement.
But just think of the aesthetic changes. @mizure3213 was able to use their North American SNES fidget toy to swap the colourway of their Super Famicom buttons. It's hardly a controller-saving repair, but it's still pretty!
The short story is, we now find ourselves wanting these controller button toys more than ever. At the time of writing, the new 'Controller Button Collection' is only available in the Tokyo, Osaka and Kyoto Nintendo stores and Tokyo's Narita airport.