This is what GCC has to say about it.
I ran into problems with EEPROM on AVR128da, Microchip Studio builds fine, but my Makefile does not like the EEPROM. On VScode, Intelasense thinks I have an "avr2" device, it is probably the same issue with Makefile. I can feed VScode (and Makefile) the define to be an "avrxmega4" device, but I wonder if there is another way that I am missing. Anyone know where Microchip Studio (e.g. new AS7) gets __AVR_ARCH__ from to pass to the toolchain.