Disappointing but not unexpected omission.
Seems to me that Southgate doesn't have many (if any) genuine game changers in his squad. Jack at the very least offers something different, and his defensive work is infinitely better than the likes of Gordon or Eze.
Southgate is clearly looking at 'going for it' this time, but his squad doesn't really look capable of adapting to a plan 'B' if plan 'A' goes tits up.
I may well be wrong of course, but I really don't see the point in taking Kane, Watkins, Bowen, and Toney. Even Rashford would offer more than Ivan Toney.