Definitely possible, a similar thing happened in both DS3 and Elden Ring shortly after release IIRC. I'd imagine this is a troll who decided to target Webfishing explicitly because of the "straight" title drama.

It's really freaky to experience it in-game. They keep joining my games, and they can't be kicked, so they just sit there, menacingly. As soon as I found out they could corrupt save data I just started leaving whenever they joined. It may or may not be true but I don't want to risk it.

Honestly, this is the kind of shit that obviously sucks for players, but is excellent for the culture, so long as it stays confined to this one account. It's a spooky legend.

ludusavi is a cross-platform program that automatically backs up game saves

manually:
Windows
%APPDATA%\Godot\app_userdata\webfishing_2_newver\
Steam Play (Linux)
<SteamLibrary-folder>/steamapps/compatdata/3146520/pfx

Thanks, forgot to mention that!