Earlier quoted context omitted.
> Does that take 6 months? If this one change is in a pool with tens of thousands of other possible changes, and it also has to go through one or more QA cycles? Sure, why not 6 months?
> Sure, why not 6 months? Because the first WWDC preview version of Big Sur was released to developers on June 22, 2020, and Big Sur was released to the public on November 12, 2020, so Apple needs to be able to fix issues identified during the beta period much quicker than in 6 months.
No OS does, including FOSS distros / OSes.
Apple just has to fix "the most important issues" with the most bang for the buck identified during the beta period before release.
Which they do.
The ones they consider less important are put in a backlog.
You can find "issues identified during beta releases" still open and unfixed for all OSes, some even going 10 years back, long after the release was out...