Shouldn't our quality filter be as strict as it can while producing accurate results? If we make it more guessy, how are new users going to learn the difference between a good question and a bad question, when some of their good questions we reject based on an unsure algorithm?
It's all the more important for a struggling (or apathetic) new user to get accurate feedback on this.
This proposal is analogous to auto-grading exams for struggling students so the teacher's time can be saved on students doing better. This is good for the teacher's workload but clearly bad for the struggling student. You could argue we should do this not to help onboarding a user but to reduce low quality question volume, on the grounds that so what if we screw it up for someone who has wasted our time once. But I suspect this will just lead to more "needsmoretextneedsmoretextneedsmoretext" in questions, making them lower quality.