Yeah, I'm working on a fly by wire eVTOL project, we are using the CAN bus as our primary bus, but there are a number of off the shelf components like ADAHRS that we use that talk ARINC-429 so our FCCs will have a number of ARINC-429 interfaces.
But at least for the components we're developing, we have basically standardized on ARM, the TMS570 specifically since it offers a number of features for safety critical systems, and simplifies our tooling and safety analysis to use the same processor everywhere.
Z80 is pretty retro, and while I'm sure there may be some vendors who still use it, it's got to be getting pretty rare for new designs, between all the PowerPC, Arm, and now RISC-V processors available that allow you to use modern toolchains and so on, I'd be surprised if many people were doing new designs with the Z80
