Seems like nobody has bothered to ever update this once the project was abandoned in 2011. I just sucked it up and manually added a bunch of games to mine (my MAME/LB bartop has about 300 hand-picked arcade games on it). Figured I could just do it once and be done with it. In the end I think I only had to manually add 50 or so... but it's a bummer that there's no real way to automate this.
For what it's worth, in case anyone out there stumbles on this thread like I did... here's now I easily got the info to add my own entries:
Look up the game here, making sure you have the arcade version... this site has a "controls" layout for about 99% of the games out there. This will let you know basically all of the info you might need to do a manual entry yourself (joystick type, # of players, how many buttons ,and what to name them for voice feedback): https://www.gamesdatabase.org/