Popa, Dayanim don’t have ruach hakodesh. That’s like saying that any judge who gives someone probation instead of prison, and the person goes on to commit another crime, should have all their previous sentencing decisions reversed, so that whoever was sentenced to probation, now has to go to prison. The dayanim have to go on what they know, based on what the convert does, and what the convert and his/her mentor says at the time of conversion. One ger who either isn’t observant or goes off the derech later can’t retroactively passul the previous converts. Anyway, I wasn’t talking about the beis din that converts the ger, but rather the mentor or sponsoring rabbi.
R’ Avis Weiss has nothing to do with this. They might have their own more lenient conversion courts now, but that’s a very recent development. Most conversions are now done by regional batei din or other well-known batei din, such as those approved by the rabbanut and the RCA, and it’s been that way for a while (even before the lists existed.)
The reason it’s a non-issue is because if the giores or any of her descendants switch from MO to Charedi, and their conversion is in doubt for whatever reason, legitimate or not, they can do a gerus l’chumra.