So, IANAL, but, reading through GoFundMe's TOS. Their weasel word catch all certainly allows for them to cancel a campaign. But it does not allow for them to transfer money to "charities of their choice".
Which means the money needs to be refunded. In which case the only potential Plaintiff would be the truckers themselves.
However, since that is not the case, they've made everyone who gave money a potential Plaintiff. With the usual bag of tricks. Tortious interference, breach of contract, false representation etc. remember, they manually approved the campaign after a short pause.
The big one I see though is "Unjust Enrichment", and this one is the doozy. Because that cause is not for Go Fund Me itself. It's for any Charity that Go Fund Me gives the donated money too. They could be sued too, and even better GFMs TOS would not apply.
The TOS for Go Fund Me only applies to Go Fund Me and the contracting parties. The Donors, the Truckers and Go Fund Me. If a Charity, being an uninterested third party accepts money that is the subject of a contract dispute, this is text book Unjust Enrichment and they can be roped into any lawsuit involving that money.
The final kicker is even if GFM gets away the charities may not. Because the bad act is not the acquisition of the money itself. It's accepting the money knowing that AT THE TIME there was an on going dispute.
