I don't know if anyone else has mentioned this before, sorry in advance if they have, but maybe there is a bit of a clue about what will be announced , if you look in the available sound files on the HM Tutorials which updated on the 19/03/24, the class 50, class 66 and Duchess sound files are listed but not yet available but it is also showing for TT , sound files for Class 37 (SD057) available Q2 2025 , just a thought