Many European travellers have already got this omicron variant, with different symptoms. I was actually due to travel tomorrow to BKK under original T&G circumstances but wifeys pre-travel PCR test turned up positive, which was a total surprise because virtually she had no symptoms at all. Better to have a positive test here than in BKK though.
We were able to rebook those flights to a later date, but now need to apply for a new Thailand Pass. It was a little bit disturbing to read about the Day 5 test, which to the information published so far, do not take into account if you have recovered from Omicron. To us it's only a money grab, nothing else. Here's hoping that they'd account for those scenarios also, but I'm not holding my breath seeing their track record so far.