I don't think there was any changes to the RNG during the 2.0 update, but I will say that the new villagers can be found on the nook mile island. Make sure you save up enough Nook Mile Tickets in order to start villager hunting, but before you do that you must make sure your villager has a thought bubble over their head and make sure you say "yes" when they are about to move out.
It takes usually two days for the villager to move out but once the plot is empty on your island that is when you can get villager hunt. The one thing you need to watch out for is duplicate villagers. Sometimes when you use your nook mile tickets you have a chance of encountering a villager that you just saw already. I also know that if you have a lot of the same species (cats for example) you have a higher chance of encountering a villager that is part of the species. I know it sounds complicated, but thats how it is.
To get a better understanding you can use this Nook Mile Calculator that way you can see how much a percentage you have of seeing a villager that you want. It may be helpful, but of course the RNG can still mess with you. Hope this helps:
Calculate the odds of finding a villager on Mystery Tour.
acnhapi.com