I'm not sure how accurate the information is, but Hal had several siblings and two children and of course a wife, so one of them could be in possession of these wallets. Somehow it doesn't seem to me that the family sold the wallets, because how can you do that without getting scammed or attracting too much attention?
As far as I can see, someone changed the password on his BTT account in 2017, does that match the signed address you mentioned?
He was dead in 2014 and in 2017, there was transactions.
https://www.blockchain.com/btc/address/1Q2TWHE3GMdB6BZKafqwxXtWAWgFt5Jvm3?page=1The below information was shared by Hal Finney and he meant his wife, son and daughter are tech savvy and know how to keep wallets and bitcoin safe. Whether their wallets were compromised in 2017 or recent years, I don't know any information and confirmation about it.
Those discussions about inheriting your bitcoins are of more than academic interest. My bitcoins are stored in our safe deposit box, and my son and daughter are tech savvy. I think they're safe enough. I'm comfortable with my legacy.