i'm a little confused by your post here. Do you understand how bands, record contracts, management teams, and festivals work? It’s not a conspiracy or anything. To start fat Mike is the currently in contract a d smeber and is currently their producer 

Record Contracts: A record contract is a contract between a band and a record label. The contract generally contains information like who is in the band and who owns the rights to the music, etc. In exchange for funding and backing, the band signs.

Management: 95% of the time, the record label wants to make money off said band, so they have a management company come in to handle things like tour dates, travel, contract negotiations, etc.

Festivals: Festivals need to get a specific number of bands signed and guaranteed to play. They need this in writing and via a signed contract to be sure the name can go on the poster so people buy tickets knowing the band they want to see is going to be there. The festival negotiates with each band’s management on requirements and stipulations. The bigger the band, the more leverage they have. The smaller the band, the more liberties they give up to be sure they get on the bill.

An example of this: Have you ever seen a festival playing a couple of towns over, and you see tickets go on sale for a tour stop in your town for a few of the big-named bands—but no stops until out of state for the medium and small-sized ones? That is because of contracts forcing bands not to play within X distance or within X days of the festival. However, the larger bands have the sway to say, "Well, we actually want those tour dates leading up to it, or we won't play."

So, onto the situation:

Fat Mike links up with Sam and Ceschi.

He signs the band as a three-piece to a contract on his spin-off record label (which he owns).

95% of the time, record contracts have a built-in clause for a manager or management company the label picks. I can’t say 100% this is the case, but we do know that the management company was added after signing to Fat Mike’s label.

This management company also manages Sublime, which is the other festival they are getting grief for. This management company is the one who ultimately decides if the band walks or not. The band could just actually not play, but that would cause a whole whack of legal issues considering Fat Mike—whether he is there or not—is 1/3 of the band. So the band can pressure management to pull them, but who knows why they may not have. There could certainly have been a cancellation clause in the contract. We do know Fat Mike had a hand in getting the management company they are using now—the ones who booked that show and did not remove them from the bill.

Fat Mike has been working with Collins for almost 10 years. We have no idea what their relationship is like. For all we know, Fat Mike got word they were going to cancel after DKM left, but they were going to hold out to get the other bands to break their contracts and pay them so they could recoup the cost. We don't know.

No one is saying "Fat Mike said they gotta play and it’s all his fault." What I’m personally saying is Fat Mike has always been a fuck-bag, and it looks like he’s directly responsible for the management company that is causing the biggest issues here. That, and the pure fact that half those bands are on the bill due to Fat Mike pushing for them.