Universal Credit Migration

I just received a letter telling me I must migrate from ESA to UC. The letter claimed that they had contacted me about this in March but I never received a letter then. I suspect the DWP is trying to justify implementing Starmer's recent cuts to disabled benefits by inventing retrogressive correspondence to validate the recent changes as if this migration was the DWP's intention before the cuts announcements. Call me paranoid!
Anyway, I took the Benefits and Work UC test and found some of the questions quite bizarre. Is lifting your hands above your head a sign that you have no disabilities and are capable of work? What a bogus question. What if you can put a t-shirt on without lifting your arms? Or you can lift your arms only when held at gun point? Or you're bed bound but can only lift your arms above your head when lying down?
What I'm asking is how do these physical actions establish someone's capacity to work? I am seriously confused about this test.