Royal Thai Embassy, London has been sending out emails today saying:-
Due to From 1 Nov.2021, all travellers to Thailand will have to apply for the Thailand Pass at tp.consular.go.th, allow at least 7 working days for approval from the central authorities. For travellers arriving Thailand from 1–8 Nov.2021, we recommend you to apply for the Thailand Pass and Certificate of Entry (COE) in case of any delays of the Thailand Pass. Those travelling after 8 Nov.2021,please register for the Thailand Pass. For details, please visit the Embassy’s website [members only]
TLDR : Answer Summary
Starting November 1, 2021, all travelers to Thailand must apply for the Thailand Pass through tp.consular.go.th, allowing at least 7 working days for approval. Travelers arriving between November 1 and November 8, 2021, are advised to also apply for a Certificate of Entry (COE) to account for potential delays. For those traveling after November 8, 2021, registration for the Thailand Pass is required. Further details can be found on the Royal Thai Embassy's website.