With work from home it would be hard for the truckers to embargo GoFundMe headquarters. GFM has a history of collecting then freezing funds for causes which don't align.
The fact that they collect them at all is what seems illegal to me. They know full well they don’t intend to pay these funds out when their politics disagree with the cause. So they’re soaking up the momentum of the movement and time of donors and then locking it away until it is irrelevant. It’s plain old political warfare.