I don't think this would be a good idea. As mentioned above the forum generally does not get involved in business, although the admins do sometimes call out obvious lies in reference to the forum.
Also as mentioned above, this would make it very easy for the mangers of signature campaigns to get two free months of advertising, since they generally payout after the next payment period starts (and after when people need to reenroll), therefore participants could be locked into a signature campaign for one month, be waiting for payment, and then having to be locked into another month of advertising, then once a lot of people have locked into a second month would it become obvious they would not pay participants.
Additionally participants may run into situations where a site scams in the middle of a payment period (like
dicebitc.in) and a lot of people would want to take down their signature to avoid advertising a scam. This is only one of many reasons why one may wish to take down/change a signature they are wearing.