Yeah that seems pretty reasonable to me. Was pressed off when the government here sneakily extended copyright length from 60 to 80 years as part of a trade deal with the UK a year or two ago - even 60 years was far too long IMO!
Not sure if this person is in the same place but Aotearoa NZ recently extended copyright from 50 to 70 years after death due to a UK trade deal, so I wouldn't be surprised if the UK have pushed it. We've recently fast-tracked the change due to an EU trade deal, though, so it's not the UK alone.