Hi freddo
ignoring the post 9/11 fall-out, it's interesting to see be reminded of some of the apparent reasoning for not moving previously.
Of course what's changed now is that they'll need a much smaller footprint - but the move was to Essex was all in place before the major downsizing - as can be seen comparing the original Essex scheme with the current one.
https://www.jehovahs-witness.com/topic/42605/reason-uk-bethel-move-scrapped
https://www.jehovahs-witness.com/topic/21046/report-from-publishing-committee
https://www.jehovahs-witness.com/topic/13739/re-milton-keynes
https://www.jehovahs-witness.com/topic/15342/wtbts-preparing-downsize
https://www.jehovahs-witness.com/topic/14670/bethel-move-scrapped