The "netwinder/ipaq craze 20 years ago" would be 32-bit ARM (AArch32), while AFAIK this new chip is 64-bit ARM (AArch64); everything has to be ported again to this new ISA (though yeah, most things were already ported for Linux on AArch64).
Yep, in the intervening time ARM on Linux became popular enough that doing the required compiler backend work for 64-bit ARM in GCC, LLVM etc by commercial interests was a given, there was eg a big push for ARM on servers from various vendors. MS even ported Windows Server. Eg Hotspot/OpenJDK was ported in 2015.