I spoke to a controller about this and he said that if they give you 'high speed', they also mean cancel 250/FL110. He did admit they should really also say this seperately, but that this is not always the case. To clear up any misconceptions, just say you're cleared high speed to the next controller (and he'll ust give you a new speed if he so desires). They almost always give you speed control, unless late at night/ really early.
Oasis.