If the Haskell compiler is spitting out "ambiguous instance of +" or whatever that error message is, it's a sign that the author doesn't understand what they're asking for. Taking a language whose value proposition is "I refuse to compile your code if there is the slightest indication that it's not perfect" and slapping a fuzzy ML model on top of it to suppress a class of errors is not a good idea.
Type systems exist as a way of ensuring that the programmer's mental model matches the code. Offloading type annotations to something else removes that safety from you.
> no priors
Sure? I don't see how that changes anything. My point is just that we already have very high quality summarizers of code, but software development is still hard. Making a model that attempts to approximate the summarizers of code that we already have isn't going to help much, no matter how good it gets.