I think it's very premature to call that. Europe is rapidly getting over Covid, and people will be itching to fly off to the sun this winter as much as they ever did before, not least because many have spent far less than usual during lockdown and are now flush with cash.
Thailand just needs to go the extra mile and ditch the quarantine requirements and other restrictions that are messing up the tourist scene, which could happen as soon as Nov 1st, but more likely Dec 1st I suspect; and see tourism from europe back to full strength after Xmas.