Well, I don't know the teams reason for not letting the signature campaign to be long lasting, but now is a good time for them to consider coming back to the forum. Their casino is gaining attention clearly with the attention this thread is having. With a signature campaign, they can cement their presence again and get some top forum members who are currently without campaign due to the campaign drought to promote them properly here.
Well, one thing I know is that during signature campaigns, the casino may have a specific referral link on that signature, or they usually know where their traffic is coming from, and after evaluating their expected traffic for the signature campaign and determining that it is not worth the money they are paying for signature promotion, they may want to stop the promotion and try other means too. I am guessing that they may not have gotten the desired traffic here. I still remember that there were some casinos that did signature promotions for just a few weeks and stopped too.
I have not really come across sportbet.one advertising on any site or social media, but I guess they may probably have another means of promoting their casino.