Controversially: It's not that urgent.
Other answers cover why you might want to change it, but they are talking about best practices and not really thinking about the exact case. I think there's value in looking at the specifics so we can learn from them (spoiler: properly hashing stored passwords is good). Let's break it down.
Background of IA's password storage:
Here's an example extract from the database, from the article here: $2a$10$Bho2e2ptPnFRJyJKIn5BiehIDiEwhjfMZFVRM9fRCarKXkemA3PxuScottHelme
.
This is bcrypt with 2^10 = 1,024 rounds, which is the default in many implementations (see here for how to parse this string). You can see that people were recommending higher rounds than back in 2015 on this very website.
It is possible that accounts that set/changed their password later (above example was set in 2020) were assigned higher rounds, but best practice is to update such things on a login when the site has access to the plaintext password, can compare it against database, and can re-hash it with higher amount of rounds (or even a different algorithm) to then save on the database again. (We don't know if the journalist logged in since 2020 either though.)
For simplicity let's assume that they were using 2^10 rounds for everyone.
Impact:
I don't trust myself with benchmarking it, but a user benchmarked it here on an Apple M3 Max CPU (albeit on Python) and each attempt to hash took 84.8ms on bcrypt with 2^10 rounds.
In bcrypt the salt is 16 bytes, the password hash itself 24 bytes. This is fairly secure against rainbow tables, so depending on your password length, if it isn't shared with a different website, isn't one of the common passwords or vulnerable to a wordlist attack, bruteforcing it is the only option left available.
Even with just a 8 character password containing only a-zA-Z0-9, even if the characterset and password length was known, that'd take 584117 years (0.0848 * ((26+26+10) ** 8)
seconds) of CPU time to exhaust all options (if running on an M3 max, probably on a single core, running in python. more optimized setups will obviously take less).
It's still good practice to do it, but I have a long and random password, so I for one am not worrying about following exactly when IA is going to return, I don't care to log in and change my password ASAP. I'll find out at some point that it's back, then I'm going to change it when I find time. In the future there may be developments in technology that cuts this time down significantly of course, so you shouldn't leave it as-is forever.