Yeah, that's counting construction jobs like the sibling said, or just unfounded optimism.
A datacenter with tight SLAs probably needs one 24/7 tech and one 24/7 security guard. That's acheivable with 5 jobs for each, so 10 jobs total. Maybe a couple more techs if the ticket volume is high. Never going to be hundreds of permanent jobs.
Yeah Northern Virginia trapped themselves with that thinking. They can't stop building Datacenters, less they lose tens of thousands of jobs in the region. And the Datacenters know this, that they can beat concessions out of politicians for it.