That sounds like a great idea. Kind of like Twitter verification except the verification that you're really a government official comes from the fact that your home server is a government run one.
And the same could go for corporate accounts. You're a public relations guy at Roblox and want an official, verified account on mastodon/in the fediverse? Spin up social.roblox.com as a mastodon server that has your PR account as its only user, disable open account registration and you're good to go. (maybe an optional dummy account to get federation going by subscribing to all known fediverse servers of interest)