Microsoft is saving their *** (backs) preventing lawsuits by companies that have malicious users that misuse the functionality and it's putting their companies in jeopardy. Probably even MSFT themselves.
There is no way to understand differently than a cheap quick solution to address a bigger legal problem that was (as usual in MSFT) badly planned with business cases being neglected. That 0.0001% of bad users that really caused trouble to their companies are the reason why 99.9999% of the good users are paying the price.
MSFT should respect the 99.9999% of the good users and re-enable this feature, and speed up a better functionality that allow each company's IT Teams to determine at account level, which individual has access to copy the contents of the Live Captions or not. It's harder than just blocking, absolutely! But that should be the right choice!
Employees don't have an option to switch to a different tool, we are STUCK WITH TEAMS! So MSFT, respect that! A worldwide subtle chance excusing in "privacy" it's so hard to buy.