Well for one, your service advisor has NO idea what hes talking about (as it also sounds to me that he is confusing the maint. required light with the TPMS warning light).
The TPMS system does NOT get reset after an oil change unless the tire pressures are changed. And even then, there isnt really a reset for the newer toyota TPMS systems, as it auto corrects itself once the tires are within +/-2 (around 2, not sure on exact spec) psi from each other. Once the pressure is set, the light should go out automatically within 5 minutes of moving the vehicle.
But now I have some bad news: On the Toyota TPMS, if the light is FLASHING, that usually means there is some sort of system error that has a diagnostic trouble code (DTC) stored in the TPMS ECU. This can include anything from a dead/damaged wheel sensor, or a faulty TPMS receiver/ECM. What you need to do is talk to someone at the dealer that knows what he's talking about
and have the pull the code and see whats up. (9 times out of 10, its a dead/damaged sensor.)