As the campaign is managing by Yahoo, I think he will take care of it. Spammer/Shit poster won't get a chance from him! I am sure you will see a lot of "woke up" accounts in Cointalk/Yobit signature campaign. But Yahoo will remove them as well!
You do not need to be worry about it as Yahoo will manage this campaign well and only good posters will remain in the campaign.
The thing which take my attention is who is the owner of crypto talk forums ? Is the the Yobit themselves because they are spending a good lots of funds to spreading this crypto talk forum advertisements here.