Yes fan tip speed is supersonic. Same as on prop aircraft. When You see a prop aircraft in the sky that is not the engine you are hearing. That is the tip of the blade smacking the air as it dips in and out of sonic.
If you have the chance to get near where the pilots are pushing the TOGA button you will hear a "WUMP" as the blades go sonic.
The amount of pressure on the engine is quite large. It can be -60 out and the blades will be amazingly hot and that is why they are hollow.
