I believe that this is part of the dissatisfaction expressed in the Telegram group. Some are not satisfied with your work but still do not want to lose their position in future campaigns.
I highly doubt that. A signature campaign participant would barely spend on something like this. They would rather create new account and wear the signature themselves after ranking up.
I agree with your opinion because no signature campaign participants would do such but rather, a competitor who have been hating secretly and does not want his or her identity to be known by the forum members.
OP was fast and reasonable enough to reject such offer as it is derogatory and an attack on the personality of AB de Royse777 who is a well known and respected manager on this platform.
I think the face behind the mask should be bold enough to come up plain and express his or her grievance or whatever they feel is not alright rather than staying behind mask to do their dirty job in tarnishing ones reputation.