Pre-early access review embargo drop for Starfield makes me think that Xbox and Bethesda are incredibly confident that the game will review well. In the past many Bethesda games didn't even have review codes sent out until a day before release, specifically so that reviews wouldn't be done in-time to influence launch sales.
https://www.pcgamesn.com/dishonored-2/bethesda-review-policy
The fact that they are sending out the review code weeks early and dropping the embargo before early access even begins makes me think they are incredibly confident. This surely must be most polished Bethesda game ever, by quite some considerable margin, for them to be this confident. Makes me think the rumors that the game was content complete a year ago and has been in the polishing and optimization phase for the entire last year were true.