Everyone should and will figure out their own policy on voting, whether to not vote on matchups with a show they haven't seen, or whatever. I personally don't think it's a problem to vote on a matchup where you're familiar with one show but not the other, in that case I'd say vote for the one you know if you liked it. But again, to each his own.
As for finding a non-geriatric group to bring the sitcom bracket into the 21st century, all I'll say is I do (kind of) envy your youth (I'm 51, not young, not ancient), but the 70s, 80s, 90s were really the golden era of the TV sitcom, prior to reality TV, prior to a zillion other channels, prior to smart devices. You'd be hard pressed to put together a worthy field of 64 going just with sitcoms post-2000.