Yes but it is important for people to note that other diagnostics can initially be done and I think they could argue about them being done when symptoms change to check there is no other underlying condition (including b12 deficiency). I'm assuming that the tests they mention would indicate the possibility of a deficiency but really have no idea.But that first line specifically refers to testing to "exclude other diagnoses". They still seem to be saying that when other conditions are excluded, and the ME/CFS diagnosis is settled upon, B12 and the rest generally should not be tested.
I know doctors like to hide behind guidelines rather than explain there in action so I think tells them they should still be using there clinical judgement. I think the real problem in the UK is that too many GPs don't have any clinical judgement.