That's sort of boilerplate though, isn't it? They reserve the right to do all sorts of terrible shit, but because most of that shit costs money they don't actually do it.
As that last suggests, however, only certain roles are eligible for the checks, those being primarily roles that involve working with children or vulnerable adults, though the full list [0] is quite interesting.
[0] https://www.gov.uk/government/uploads/system/uploads/attachm...