They could and will work automagically. The infastructure is provided and or will be adjusted. FWIW so too is a generic icon. See /usr/share/pixmaps/core.png. However if an extension maker deems not to use such or only upon request, e.g. mc, then so be it. It will not be for lack of base support.
Your question has brought to light valuable insight from a user's perspective. I hold no hard feelings towards anyone. It is an interesting topic discussion which will make Tiny Core only more capable going forward.