For BA flights this is clearly written on BA's website. However, for EI flights the website just says "Avios award table up to and including 30 September 2023" and "Avios award table from 1 October 2023", so it's not that clear.
Also, please note that the cut-off date of Oct 1 is different from the one relevant to BA flights (Oct 18).
Is still the booking date the one relevant for EI flights?