It generally is offered to me, but there are circumstances when it won't, in particular if travelling in the next 21 days. Almost any complexity will also remove the offer, and there are some markets which are ineligible. The one thing that has changed is that instead of a big icon on the screen, the new-ish layout now just a small line in blue opposite the big black and bold price on the rght of the screen. If you end up on the older layout it's somewhat more obvious.

https://www.flyertalk.com/forum/british-airways-executive-club/1970289-hold-your-flight-price-tickets.html

https://www.britishairways.com/en-gb/flights-and-holidays/flights/hold-your-flight-price