I don't know of a way to prevent someone from submitting edits following validation the way you can with apps like Survey123, but Map Viewer forms do let you create Info elements that can be conditionally visible based on the result of an Arcade function. You could create a function that performs validation and if it fails, make a warning with a descriptive message visible to the user.
You could also use these types of functions to write to a hidden field indicating whether someone submitted a record that had one or more validation failures.
