I don't think so. I think you're likely to get tainted coins out of lightning, even if the coins you send in are untainted.

This largely is not true. While privacy on LN is still being evaluated, it is also extremely complicated. There's no easy "privacy on LN" guide that's industry standard, for example. Monero comparatively is much older and much better understood on the privacy side (eg: see Breaking Monero).

it's gonna get even more interested when lightning channels look like normal transactions because of taproot