Rals 7 link to request format use turbo_frame_request?

I am confused when using turbo in rails 6.1 when reading the development log– with Link_to method :get in side a turbo frame The logs said request.format = turbo-stream in rails 7.01 they say text.html but turbo still seems to work ie it just replaces the frame with new content if I submit a forming the logs it says request.format = text/vnd.turbo-stream.html

I have found now that in the controller I can use turbo_frame_request?, apparently supplied by the gem to find out f the method is from turbo

This is quite a big change and un documented or have I got things wrong?

Thanks