he/she is indeed liable to be run out, NJ, but there are howls of outrage every time this happens, on the grounds that running someone out when they deserve it is Not Cricket. Bowlers may not trespass, batters may.
The usual form in cricket is for the bowler (or his captain) to give the batsman one warning that if he continues to make his way halfway down the wicket before the ball is released, the bowler will indeed run him out. That's "cricket", though it's not necessary within the laws.
I've only ever seen this done once in First Class cricket and the batsman did indeed receive a warning from the bowler (just a couple of balls earlier, within the same over). He actually held on to his delivery and confronted the non-striker who was then about a third of the way down the pitch. There were no howls of outrage; there is no reason why the non-striker should be allowed to get away with such a practice. You may as well say it is unsporting to run somebody out in the normal way.
I watched some of the men’s matches including the final last night and really enjoyed them. But I like 20/20 anyway. Always watched on record though so I could run through all the punditry, silly interviews of ‘pop and hip’ people and children (ugh!) and the ghastly half time entertainment. The presentation was obviously aimed at younger audiences (fair enough) but the cricket was good fun. Poor ‘people’s champion’ Liam Livingstone’, run out by one of the longest throws at the wicket I can remember.
I enjoy all of the shorter versions of the game. Witness the number of family groups enjoying a game, sparking interest amongst youngsters who would not 'survive' a multi day test match. My only gripe was with the on-screen graphics which were far to big and garish.