I agree that it's desirable that any proposals can come to review, because no proposals would be accepted nor even rejected without official review state.
On the other hand, as for SE-0483, I suspect the reason why some folks surmised that there were biased things was because one of the authors of the proposal was at Core Team and Language Steering Group.
By the way, Testing Workgroup recently showed some principles of reviewing proposals written by workgroup participants.[1]
I wonder if such rules could be applied to other groups not to incur groundless suspicion.