

Do you have a static IP address? CG-NAT has done a really great job of hindering torrents, since my understanding is that at least one side of the connection needs to have an open port. So, if you don’t, then only the few people who do are able to download from you, which can make it seem like no one wants your stuff.
If he wanted to give it to the public domain, you don’t need creative commons. CC0 is public domain, but you don’t need to use it, the copyright holder just needs to state “I dedicate this media to the public domain” and bam.
And any copyright they still have over their media isn’t “forever”, it will expire eventually. In the meantime, yes their estate likely has the rights, whoever that may be.