I actually just wanna go over all the evidence there is/was for which side (3 star fam or cassie's dad) was in charge of mxes
people who believed cassie's dad built mxes had theories for a while before any info past hw2/I think during the ruin era too that because he was a technician, he had the resources and brains to build a machine like m.x.e.s, mxes was connected to the ar world, and technicians have vanni ar world masks by default. mxes also is designed after a rabbit and has very similar chest patterns to glamrock bonnies bodysuit, and like the only thing we know about Cassies dad is that hes a fan of bonnie
a lot of this stuff has been disproved. first of all bc it's been recently revealed in the past couple months during the john fuhnaff + steel wool interview + this Tuesday update that m.x.e.s is an old supercomputer from the 80s and was designed to look like one. the mxes ending in the hw2 update also shows them in rabbit form outside of the computer resisting before getting sucked back in. this scene is implying that mxes was FROM the sotm factory/the circus attraction it makes things for, and they have their rabbit form BEFORE the person driving the van takes them, so that's confirmation them was capable of having that form before it got taken. meaning nobody programmed/upgraded them to be able to do that, they already could
meaning that Cassies dad no longer has that design aspect adding to his evidence pile bc he wouldnt have a say in m.x.e.s' design
the mxes machine ALSO is very dirty in the van scene, just as dirty as it was in ruin, so that means it's pretty close to modern day, being pre ruin but post security breach. with this in mind, gregory vanessa and Freddy would all be outside the pizzaplex with a job to do at this point, and their footprints are clearly seen during ruin around the map out of the way of roxy raceway, meaning they had business elsewhere that wasnt just a straight beeline to where the mimic is, which could be concrete evidence they're responsible for the nodes that are connected to m.x.e.s.
Gregory's backpack is ALSO in the exact same basement m.x.e.s is in ruin, plus Gregory tells cassie that he knows what m.x.e.s was designed for.
that's a lot of red threads connecting Gregory vanessa Freddy and mxes. not to mention how Cassies dad canonically dies at the end of hw2, which if he was the protag would be a prequel to ruin. an unknown amount of time yeah, but the info that hes dead before ruin where mxes is found and already set up is important to note
but with Cassies dad, I think most of the evidence ppl had was just the nature of him being a technician, and the fact that he EXISTS as a character, so he has to have SOME kind of importance. that thought process makes sense but with him being immediately killed off in help wanted 2, it feels like he was just there to serve the plot, not really do anything. he was just there to be the one to help vanny kill glitchtrap, and be the player character they needed in hw2, and just. I dont know. he doesnt have a name or a face or even any connection to mimic at all, so what motivation would he have to go take mxes from the factory, the computer that was specifically built to combat mimics ai? and how would he even know its there?
cassies dads character is very confusing and weird lol. but I think that Gregory freddy and vanessa actually have a lot of concrete evidence drawing a red thread between them and mxes, and I think this van ending might have been the thing to finally prove who it was. it revealed that neither side had a hand in reprogramming it, so the design hints are out the window, and all that's left is motivation to take it and the knowledge theyd have to find it, which they definitely have. plus ALL that ruin evidence its just. it's a lot pointing to them. they're the number 1 victims of the mimic, so everything just makes sense here