Not sure if anyone is still interested in this but it is very revealing (from about 30:15):
https://www.youtube.com/watch?v=wT7g5fqh8Ec
Basically the devs are saying the modern cars were finished but we didn't have time to fix the historics properly... claiming they didn't have drivers who could offer real feedback. A weird excuse - I suspect there are a dozen people on this rally forum who could have provided real-world feedback. Seems like they just added a feeling of weight without sorting out the implications of that for the overall handling model.
Didn't have time to fix it doesn't really wash. I'm glad these guys are doing computer games and not working in my local garage...