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.
It's very much possible that in such a case all the mentioned members get wiped from both levels at the same time.
In order for a qualified person to be excluded from both DT1 and DT2, all of the people that are qualified have to not make the random selection too. Using
this calculator here are some of the odds with a pool of 250 qualified individuals.
0 others included: 60%
1 other included: ~36%
5 others included: ~4.5%
10 others included: ~0.3%
20 others included: ~0.0012%(~1 in 833)
25 others included: ~.000066%(~1 in 15,385)
So yes, there is a chance. However, I think some of the premier DT1 candidates would easily have 25+ other qualified candidates include them. I really don't think many scammers are going to get lucky and find their red scores erased, especially those with double digit red scores and lower.