Most likely current or 2021 new cars can be easily adapted to ’22 rules as the hybrid system is due to be compact and work complementary to the exisiting ICE (apparently placed on a box at the rear of driver’s seats). Besides, spaceframe chassis will be optional, not mandatory (probably used by manus with only SUV’s or crossovers on their range).
It worth to take a look on FIA hybrid system tender: https://legal.fia.com/web/appeloffre.nsf/F1AA7144B5082934C12584D500563B6B/$FILE/ITT%20WRC%20Hybrid%20System%202022-2024_Final%2019.12.2019.pdf?openelement