My brother and I have recently hopped back into Minecraft, it has been a little while. There are a lot of things that are new to us but we do remember seeing rabbits, although not pig, cow, chicken, or sheep common but common enough running into them wasn't a question of their existence. 

However, we have noticed the lack of them in every biome we have passed through and there just doesn't seem to be any of the furry little fellows anywhere. I checked to see if there were any reports and any I saw was clear back in 2016 or 15 but not recently.

We perhaps thought you might have changed the frequency of them spawning or location but they just don't seem to be anywhere. 

We have started other worlds and have seen the same similarity of lack or non-existence of long-eared rodents. Hopefully this is just poor luck rather than a bug but thought it would be best to report just in case.