It’s based on your country and language settings so if BA decides to give you the French website you can change it back to the UK website and get English titles.

I’ve had Spanish and Italian titles on my boarding passes before and it’s caused not problem even when the order has displayed odd on my boarding pass.

I can see why you’re worried about the title looking like a middle initial but in reality you’d have been ok.

I did have the person in the cloakroom in the CCR thinking my name was ‘Dott’ when my boarding pass had an Italian title on it as the order on the boarding pass was a little weird