"I want to do X" / "I am too lazy to do Y instead" becomes "We can't do Y, it's a mandatory requirement to do X"

Very high on your response agenda should always be to ask for details. Who mandated this and how? If there's a regulation, cite the exact text of the regulation. There's a good chance the person telling you it's mandatory either knows it isn't or has never actually wondered why, and you can divert them from insisting on doing X / not doing Y to an exciting journey through their bureaucracy to find out that indeed there is no such mandate and never has been.

Back when TLS 1.3 was being finalised EDCO and other groups trying to preserve RSA key exchange tried really hard to pretend that what they were doing was mandatory (it isn't and wasn't) and that their use cases were legitimate (most of them don't even appear to have a sound security rationale, let alone a legitimate purpose).

When we get to September and companies that were asleep at the wheel suddenly notice the 398 day rule (Apple unilaterally changed the maximum lifetime of new certificates in the Web PKI to 398 days starting in September) you can guarantee that some of them will insist that having longer-lived certificates is somehow mandatory.

[ Edited: It's the Enterprise Data Center Operators thus EDCO not ECDO ]