All that they already got when i started the account, what they want to know is pretty much all personal data one can have about a person.
Strange this was no issue for two years prior, on top of that it is very hard to impersonate in Finland given most registries are open to the public, if you have cause and Airbnb very easy can proof that you can very easy verify a persons identity, usual by using the online banking systhem as usual, pretty much all online accounts in Finland use the banking accounts to verify identity, and theese accounts use two source and tan systhem to verify the user, you need to obtain a persons password, smartphone and tan's sheet if you want to impersonate, someone with that much criminal energy would beat any other systhem too with ease.
There is zero reason to milk hosts for personal data.