After trying to link a couple of suggestions that weren't mine in chat, I was told by Modbot:

From Code of Conduct: Do not post content or links relating to other user's accounts, sales, raffles, lions etc.

Why does this rule apply to suggestions? If there's a problem with people over-linking the same topic in chat it can be handled on an individual basis. People should have the ability to link a topic they care about even if the original publisher has forgotten about it, especially so reposting the same topic on forums can be avoided more easily.

Edited: A requirement to give consent on the forum for others to link your topic in chat.