I like Michael's original suggestion that there should be two meetings in the last five and if there is not a third, then meeting some other requirement, a choice of things like attended lots of past meetings, has a defined role in a wg, ...
Others have noted this, but the two important goals of these criteria are:
Has attained a (minimal) level of familiarity with IETF
Has a probability of attending in person for the Nomcom activities
Michael has crystallized in other posts the fact that Nomcom really needs the in person time in order to work together, and IETF teally, critically needs full attendance if Nomcom during the meeting(s) with interviews, especially November, for the candidate interviews.