Bottom line we cannot jump to conclusions how this issue ultimately made it's way into the final release.
Bottom line is, if we are to use your explanation to defend the results of this latest release ... Adobe are either incompetent, inept or both. Either way, not a promising perspective that builds customer confidence.
There is no need to 'jump to conclusions' as there is ample evidence that once again, someone at Adobe we are paying to serve our needs, failed to live up to their end of the bargain. The fourth such occurrence since Lr CC 2015/v6 was introduced. Not to mention their first response was to place blame elsewhere instead of reviewing their own work first.
This problem seems to be systemic of late and not a result of isolated or unintended
'whoopsie daisy' mistakes that occurred by chance. It was a result that was due their failure to adhere to a more stringent level of quality checks and balance that could avoid the situation. It would be much more reassuring to we end users that they would hold themselves to a high standard. To them, we should be worth the effort.