The law probably qualifies as an ass re. this overtaking rule. I can't see the enforcement regime changing, so either this means doing research & increasing the threshold to an updated '25' mph, which may be neutral or worse wrt cyclist safety.
Status quo is more likely, with cyclists being deemed to forever be doing <10mph. I have heard that that 10mph was set aeons ago when most motor vehicles accelerated like slugs, but then the traffic density was far less than nowadays, which possibly partly nullifies the effect of faster accelerating vehicles(?)
Have I mentioned Presumed Liability..?
As a potential general dampener on drivers doing stupid things around cyclists...