I can see both sides here. For instance, I can understand why someone wouldn't want to see their idea portrayed in a way they might not like by someone else because they would be emotionally attached. This is especially so if they’ve explicitly said upfront that they don’t want anyone to continue, then ethically, yes, they have some say. But that say is moral, not enforceable. Once something’s shared in a public, collaborative space, control becomes pretty blurry. Hence, why they should do what I've seen an old GM do, which is restrict, if not completely block, access to what they see as their intellectual property (e.g. taking their information off the guild). So, all in all, the best I think we can all do in this kind of situation is aim for a middle ground. If people want to respect both sides, they could:

Reimagine the setting (change names, tweak lore).

Credit the original inspiration (“based on the concept by X”).

Avoid direct reuse of their writing or world details.


That way, it’s not continuing their work. It’s inspired by their work. At the end of the day, once you involve and collaborate with others, you can’t blame them for at least wanting closure for the connections that THEY created (i.e. exact name and lore is off limits).