For example HodlHodl is classified as KYC level 0 but they have this in their ToS
3.5 Identification and Verification
If required by applicable law or our internal policies, we may at any time introduce mandatory identification or verification procedures. Failure to complete required verification constitutes a violation of this Agreement and may lead to account suspension or termination.
I think it should be somewhere at KYC level 1 or Am I missing something?
Actually now they are performing AML checking and automatically rejecting high risk coins for trades.
So while it's definitely not KYC, it's still quite bad to interfere with two consenting traders.
I guess they got spooked by the NoOnes situation.