Oil pump priming. Vaseline needed?

It isn't required on a big block Mopar. That is an old Chevy trick where the oil pump is hidden inside the pan and you really don't want to take it all apart to get it to prime. On a big block Mopar the pump will prime 99% of the time if some oil is poured into the oil filter. Sometimes you'll get an air bubble in the system but those are easy to get rid of. Just crack open the filter and spin the pump to purge the air and then you'll be primed. The guy who did the video most likely isn't a Mopar big block guy, maybe a long time Chevy mechanic who just uses the same trick for every engine whether it needs it or not.