I already wrote that I don't think that the reason is money, considering that the pay rates on this forum are 4-5 times lower than they were on BTT,
The Mixtum campaign paid a maximum of $52.5 per week, which was the highest on this forum. Also, (I didn't count precisely) a large number of campaigns on Btt are in the range of $50 per week.
So, in my opinion, there are two possible reasons - the first is that they estimate that the forum is not bringing them the desired results - and the second is that maybe they started a new mixer that they want to give better visibility. I have no doubt that the same people are behind some mixers that exist today.
It is possible, but it would also be strange because every mixer depends exclusively on promotion. You can have a mixer service, but without promotion no one knows about it and no one will use it.
Also, if you are already investing significant money to promote one brand, leaving and switching to a new one would mean that all the previous investment in marketing was a waste of money.