Yeah, MMBasic probbably won’t work on them without someone from the community to do the porting work. MicroPython has been shown to work on the WalnutPi. And all the usual build tools for C, CPP, Python, Perl, PHP, and whatever else you may want will probably work on the Lyra since it’s running full blown Linux. Someone already has Pico-8 running on it, a Doom port, etc.
If you want MMBasic/PicoMite, best to stick with just the Pico or Pico 2, or a Pico upgrade like the Pimoroni (as I imagine someone will get PicoMite working on it too). That will also be compatible with the usual Pico development tools and information online. But if you want flexibility and a sort of “mini uConsole” (obviously with much less power), then the Lyra would be the way to go. A recent post indicated the MilkV Duo may also work as a Linux solution, and it seems comparable to the Lyra (and also has support for adding a camera, which would be interesting to see someone to try to integrate into the PicoCalc case!) For these sorts of things, the PicoCalc ceases to be just a “calculator” and is more like a case for a SBC Linux device with a nice built in keyboard and screen.