Unlike SD I don't think this is nonsense at all. I see exactly where you're coming from. The difference perhaps is that we've won a few games under Sage (albeit in cups mostly) which we didn't get under de Boer. Plus, Parish found speaking to de Boer only added to his concerns.
We don't know whether Parish finds Sage far more reassuring when the two speak.
Ultimately, the nature of the performance at Leeds indicates that perhaps Sage can adapt (or at least successfully implement) his approach. De Boer couldn't. If we see more of that stability in coming games then Sage should be fine. As you say, though, if not then I wouldn't be surprised to see Parish pull the plug.