QuoteTrezor states in its post that it "will never contact you asking for your wallet backup." Whoever asks for it is therefore not the vendor. The same rule covers banks, mail providers and any account with recovery codes.
This is the most important part. Nobody should every ask you for it. Whoever has a cold wallet should know this in the first place. And to remind oneself, put a reminder somewhere where to reminds you every day that nobody, even the wallet makers themselves, has the business to ask you for your recovery phrase, otherwise it IS a scam.