How should one come to a solution then in your opinion?
I think calling it brigading might be a bit harsh. Precisely because it is directing people to one very specific link (and only telling them to give a thumbs up), which while not as relevant to development as discord, still is the most relevant place accessible to all. And it can be ignored easily enough by just closing the issue.
By that definition creating and sharing a petition is pretty close to brigading as well.
(There is of course the risk of people taking it too far, whenever someone with a lot of clout addresses anything and I can agree that it might have been the responsible thing to say something like "please don't bother the devs with that elsewhere")