In case there was confusion: Python's f-string functionality in particular is specific to string literals. The f prefix doesn't create a different data type; instead, the contents of the literal are parsed at compile time and the entire thing is rewritten into equivalent string concatenation code (although IIRC it uses dedicated bytecodes, in at least some versions).

The t-string proposal involves using new data types to abstract the concatenation and formatting process, but it's still a compile-time process - and the parts between the braces still involve code that executes first - and there's still no separate type for the overall t-string literal, and no way to end up eval'ing code from user-supplied data except by explicitly requesting to do so.