[aix1]

In theory, yes. In practice, it would take some pretty extraordinary circumstances for one to get promoted without their manager's support.

For starters, even if it is the candidate themselves who self-nominate, it is still the manager who writes the promo readiness assessment that forms the main body of the packet. It is also the manager's job to solicit peer feedback and represent it to the committee.

One could imagine a scenario where the manager's opinion diverges sharply from the assessment of the session lead and other senior folks sitting on the committee (who decide collectively) but again, those would be some pretty exceptional circumstances...

Layered on top of this are promo quotas, which already mean that some folks who do tick all the boxes aren't getting promoted as soon as they would be otherwise (or at all). That is to say that there are lots of headwinds even if the manager is supportive, let alone when they aren't.