What about the scenario that CC users lost their coins. Isn't there plausible deniability that they are no longer in control of those utxo's. And then for that matter, other is h situations?

That's what I mean so it doesn't matter if they used Bitcoin or not, that person was already on the radar for something, made a mistake in there opsec that lead to an arrest, then chain analysis was used as additional evidence against them.