I’ve been tempted to do this sometime, but I fear the prior is performing one very important role you are not making explicit: defining the universe of possible hypothesis you consider.
In turn, defining that universe of probabilities defines how bayesian updates look like. Here is a problem that arises when you ignore this: https://www.lesswrong.com/posts/R28ppqby8zftndDAM/a-bayesian-aggregation-paradox
Here is a “predictable surprise” I don’t discussed often: given the advantages of scale and centralisation for training, it does not seem crazy to me that some major AI developers will be pooling resources in the future, and training jointly large AI systems.