Who knows?! Most places, they seem to indicate 235 miles. I'm only seeing 250 on the main web page, though not in the Compare Models specs on that same page.
So, it does seem that there will be two different versions: GT and GT Performance. Maybe the Performance package is targeting 235, while GT is targeting 250?
Also, in multiple videos of Ford officials that I've seen, they'll say "AT LEAST xyz miles" so it seems these "targeting" numbers are being viewed as conservative figures by Ford's management.