I would say that there is some truth to that, but I wouldn't hang my hat on it.
There's a kid out of my son's HS who is a LHP and garnered little to no interest beyond HS. He pitched JV as a Fr & So and didn't make the team as Jr (he was caught with beer on a Saturday night by cops, so coach cut him as a Jr). He did make Varsity as a Sr and threw limited innings (4.1 out of a total 189 innings pitched by the team).
He put together a video and played with his summer team, still no solid opportunities or offers. Out of the blue he gets a call from a JC coach in California who offers him a position on the team. Completely based on him finding and watching his video. Coach had never seen or met him in person. He had a bit of a roller coaster Freshman year on the mound in '15, but has put in work in the offseason, added some weight and had a good fall. He's talking with and getting interest from several Florida teams (D2 & D3) where he hopes to land a spot for the '17 season.
So it can and is done, but I would suspect that it would mostly be smaller schools with little to no budget to recruit outside of a very short radius.
Given the work I know you've already done with him, I'd add a good video to the toolbox you're already putting together, but wouldn't hang all his hopes on a video.