Absolutely. I have no idea how they plan to administer this 3p/mile tax - For example, I drive around 18-20k miles per year (£540-600 tax / year potentially), but some of that distance may be in my own (company) car, some may be in a customer's car (eg delivery of a new car, or collecting for service etc), and some may even be outside of the UK (for example if I decide to take my EV on holiday to Spain).
I also drive a few thousand miles per year when reviewing new cars for my YouTube channel, although none of those are registered to me.
How might it work with ex demonstrator cars? Say the ex-demo car has 2000 miles on the clock when sold after 4 months - is the tax for 2000 miles paid by the dealer at the point of sale? Or does the mileage not get checked until the annual service, or 2nd year service (depending on the interval from the manufacturer), or the first MoT point at 3 years old?
I think there could be a rise in "mileage adjustment" services offered by unscrupulous businesses too...