Facts and information don't matter for some people
The problem is that most people stopped conscious reading nowadays.
The first order 'why' is, yes. It would not surprise me that Microsoft expects a discreet call from Westminster, and after a 25 year discount on electricity fees and business rates (or whatever) has been secured, they will, after careful reconsideration, arrive at the conclusion that after all, the UK is indeed the most appropriate location for the DC.
That doesn't solve the compliance problem: data about EU customers can't be stored outside of the EU. So Microsoft will need continental data centers anyway.