Mad Flt,
It comes down to terminology and which options are taken.
Yes, some Boeings have TO De-rate as an option in the FMC, which programs a different Max Rated Thrust. I've only ever flown a couple of aircraft so equipped, so it seems a fairly rare fit.
Most operators simply use Assumed Temperature (Boeing- speak for Flex), whilst leaving Max Rated available. Entering an Asuumed temp causes the system to annunciated D-TO for Derated Take Off, even though Max Rated is still available be pushing TOGA (although NOT on the ground once the AT is in HOLD mode above 80kts) or simply fire-walling the TLs.