Well, the text-to-thought direction feels less sci-fi, and combining both would amount to kind of telepathy.

But sure, you're right. Reading is not a deterministic mapping of text to thoughts.

Apart from the trouble of defining what a thought is, independent from the person who thinks it.

Me thinking of grabbing a mug of coffee is a different thought from you doing the same... defining "thought" pulls in a whole jungle of epistemology (maybe I should say philosophy, more broadly, I'm not in the field).

Is there an abstract concept of "the thought of raising your left index finger"? Or "the thought of remembering severe pain"? Etc etc