It's not clear what Tesla actually means when they say "E2E". The expectation most people have is that there's a single NN between sensor data and steering wheel/pedals out. Based on the limited technical detail available from "AI day" and such, what they're actually doing is more along the lines of a bunch of ML models glued together in a pipeline.

Now you might ask why people talk about Tesla E2E all the time if it's not clear exactly what it is. I don't know either. Let me know if you figure out a charitable rationale.