"Just in case the Law was not clear enough, the ICC Playing Conditions for Twenty20 international cricket state:
For the avoidance of doubt, if an umpire feels that a batsman, in running between the wickets, has significantly changed his direction without probable cause and thereby obstructed a fielder’s attempt to effect a run out, the batsman should, on appeal, be given out, obstructing the field. It shall not be relevant whether a run out would have occurred or not."
https://www.lords.org/news/our-blogs/the-laws-blogs/the-laws-blog/jason-roy-obstructing-the-field/