To answer some of the above..............For most of the last 3-4 decades BA never had Turkish recorded messaging until IIRC 6-7 years ago, since the early 90's all BA messaging and announcements had always been solely in English (yes maybe I recall one or two times that they have actually had a Turkish speaking FA that did it in Turkish)..........DaveS.That is because TK does not quote incorrect information!
Pucci, regarding visas, for Uk citizens it was as you stateuntil they switched over to the new airport in 2019. At that time they really pushed the online visa beforehand, but did not make it a requirement. With the new airport, they said that it was online only, but everyone knew that there was a desk at the airport and those that slipped by could buy a visa (although that visa at different times was a bit different.........5 dollars more, or limited to one entry. However after Covid they removed visa requirements for the UK, and then about 4 months ago from US visitors. BA's "verification" system does not seem to reflect this, or only does so hit and miss.
Just to reiterate, my biggest problem about the spoken announcement, other than the announcement itself, was the statement about it being ILLEGAL, and about fines and jail, and then why and how this could happen. Was it some probably progressive person with less sense than knowledge, who decided that this is the case, and slipped it into their Ipads?Was it some sort of Muslim extremist, who slipped it into the Ipad. I mean some one had to go out of their way to do this, as the announcement is normally plain vanilla, "Welcome to Istanbul....The time is...........Please remain seated..............You can now use your phones, etc"