This has been around for a while and has been used against me in several matches before. The first heavy and light melee are done with a keyboard keybind. The second and ensuing light melees are done with the scroll wheel allowing you to override the animation for it. Not game-breaking but...
Found a few areas across the map where Phantom Strike can be used to teleport into if you or the person your TP'ing to moves behind the wall or object between you
This first one is a recreation of another clip i saw. An Abrams went to use Phantom Strike while a Dynamo standing near this pillar...
Recorded a few videos showing some weird interactions, bugs or oversight with the "rest hero" function in Hero Testing. In total there is 14 heroes that have some type of breakage when reset hero is used during the usage of an ability with 3 of them causing my game to crash to desktop each time...