There's talk of it happening regardless, as without the EU there's no requirement here to use SI units - and one pundit even suggested a return to pre-decimal currency.
Either way, people tend to value tradition more than progress or rationalisation. Having a system of weights based on the weight of a grain of emmer wheat is preferable to plenty of people, who don't have to write code or multiply weights or do science, and just want familiar human-scale units. Hell, I'm sure plenty of the aforementioned would prefer imperial too, for the same reason.