I've not noticed any issues with palm-rejection when typing on Linux. If your trackpad does have issues, you can disable it while typing (but most Windows Precision trackpads work fine).
I'm mostly using the Magic Trackpad on my desktop though. It's very possible you might find a laptop with bad palm-rejection firmware, but I don't think that's an issue with these. Or Synaptics touchpads, in my experience.
I've had problems with palm rejection in MacOS on the M1 MBA; nowhere near as bad as on Dell machines running various flavors of Linux, but they are there.
Heh, interestingly I also noticed more problems on my 14" M1 MBP than I had on my previous mid-2014 13" MBP (or more specifically: any problems at all, because the touchpad on my previous MBP was pretty much perfect).
I suspect it's simply because of the bigger touchpad. Even if the "error rate" is the same as before, there are just more potential errors because of the bigger touchpad surface.
I'm mostly using the Magic Trackpad on my desktop though. It's very possible you might find a laptop with bad palm-rejection firmware, but I don't think that's an issue with these. Or Synaptics touchpads, in my experience.