The CGI trailer was made a long ass time ago, before the game was even announced, it was likely going to be the announcement trailer, but they wised up and realized if they wanted there game to be taken seriously they needed to come out with gameplay first. I guess they just never found a right time to show the full trailer since they never actually released it, it just showed up on youtube a few days after the game came out, not even on the MK account. So yes, at such an early time, that very well could have been one of scorpions proposed fatalities.
As for the quan chi fatality was most certainly scorpions at first, but people complained that both of his fatalities were way to similar, so they gave him a new one, and instead of just throwing the old one out, they just gave it quan, shame it was probably at too late a stage to use that neat sword model for some of his dialed combos.
