Most of the DT1 members who are not on the list this month are on DT2. So their tags will still show up with default settings. The only tags that will end up missing are those left by people who would have been DT2, but all of their sponsor(s) is/are no longer on DT1.

This is nothing. Wait until the list grows to over the desired 250 people (most of which will be neutral when it comes to their trustworthiness at best), and then a month comes where most old DT members don't get selected. That's then the real fun begins.