Only if the service they're using is secure against reuse of previously abandoned names/ids. Which any such service ought to be, but we can't count on that in the general case.
Hey, as long as the crate author is aware of it, does it matter? We mean... it's just some money? Why should we care if we die and our patreon's ID becomes someone else's? We'd be dead...
Hmm, alternative thought: show the crate's short description when building.
- Compiling foo v0.1.0 (A simple example crate)
and then the crate author can throw the donation link into it.
At the very least, the donor would care that they lost money without achieving what they thought they were getting out of the money (donating to the crate author(s)). Also, if the name reuse was a deliberate scam, we could count "a scammer gaining money" as a harmful outcome, since it encourages further scams.
Yeah, should probably use an UUID-based system. Not sure if Patreon has one of those... But for the most part it doesn't really matter.
(Unless you're one of those ppl who particularly enjoy shafting other ppl for your mistakes we guess... But we digress. There's so much stuff that can be talked about money politics that it's just not worth going into in this discussion.)
Taxes. Just because you're dead, doesn't mean that your estate can't be taxed, and your patreon may be a part of it1.
So, let's say that your patreon (or whatever) accumulates a pile of cash, but your heirs don't know the passwords for it. Governments might not care that they don't have access to the funds, and demand that they be paid out of the estate from other, more easily accessible assets, leaving your heirs with less simply because they don't have the right passwords.
I'm not claiming that this is a critical point, just pointing out that there can be real-world consequences to that kind of neglect.
1I am not a lawyer, nothing I say is either legal or tax advice.