Could be but I don’t know QM well enough to say for sure.
If I understand it correctly, the collapse of the wave function is when the probabilities change at the moment of observation or measurement. So if one holds that the wave collapse is a metaphysical event (and you agree with Jaynes that probabilities are epistemological) then that would be a case of what Jaynes called the mind projection fallacy. Much of the debates in QM regarding wave collapse revolve around exactly this point. Of course, camps have formed on both sides of the dichotomy and I don’t think it can be resolved by just asserting that probabilities are epistemological. The error is deeper than that and I suspect QM needs to be derived from bayesian principles but I am not sure that bayesian probability theory is yet up to the task. The situation is very similar to the ancient debates on whether color was a property of the object or in the mind, which makes me think there is an object/subject distinction that is being missed.
Just read the Less Wrong sequence on QM. All the answers to your questions may be found there. I consider myself an aspiring disciple of Jaynes, probably as versed as any living human being in the ways of the Mind Projection Fallacy, and MWI is the version of QM which does not have such difficulties.
You’ve certainly arrived at the correct website to find the answers that you in particular seek, fellow Bayesian and Jaynesian; but you’re being voted down because you haven’t read the existing material.
Right—but there’s no collapse in the MWI. Everything remains in superposition forever—thus the “many worlds”.