I can assure you it is absolutely true. The airline staff announced on the intercom that tourists had to complete a TM6 form. I double checked with them as I found it odd too and was told I didn't need to complete one. It was post covid but before the TM6 was suspended. I don't travel out of Thailand that frequently so I'm very confident on when it was.
I'm telling you a lived experience, it was around a year before they suspended TM6 cards. I was told not to complete one by the airline staff because I was on a Non-immigrant visa and wasn't asked for one at immigration either. You can believe me or not.
I understand it affects us all, but the question will always be what defines a resident. According to the dictionary its "a person who lives somewhere permanently or on a long-term basis", that rules out most of us I'd say. I do remember flying back from a visit to the UK a few years back where only those on tourist visas or coming in visa exempt/waiver/VOA were required to complete TM6 cards by the airline staff, those on Non-immigrant visas didn't have to (from memory that was in 2021) which seemed sensible to me particularly given we're meant to file a new TM30 within 24 hours