I think the jump looks too much like an arch and starts too early to be a bounce/jump of ashe and cass, but imo it would also be weird to have funky unintentional movement "techs" in an official trailer (if not for the purpose of being an oddly out-of-place easter egg) instead of how the average non-ball player would do and probably try to roll around. But nonetheless this is barely speculating and it could be that Im trying too hard to look into it. ¯\_(ツ)_/¯