Is there a way for blockchain analysis companies to know if a transaction went to, or came from a mixer/CoinJoin?
Yes. It is trivially easy to identify coinjoin transactions, regardless of which coinjoin implementation they use. The benefit of coinjoins does not come from obscuring the coinjoin transaction, but obscuring which coins are which.
They may never have the ability to connect our coins after mixing/CoinJoin, but because there's already some "information" that those UTXOs went through a mixer, then therefore they are "tainted".
"Tainted" according to their provably made up bullshit nonsense. As I've said before, I have never once had a problem with any of my well obfuscated coins being accepted anywhere,
because I flat out refuse to interact with any person, service, business, or other entity which attacks bitcoin by buying in to the nonsense of "taint".
I have nothing against Wasabi's when they made the decision to work with a blockchain analysis company
I do. It's a direct attack on what makes bitcoin bitcoin, and paves the way for government take over.
But that's precisely my point. It could build a separation between "tainted" Bitcoin and "clean" Bitcoin, and that could make people value them dfferently. Currently we're not in a "taint-aware" world, but the shower-thought - "What if wallet software developers start implementing alerts that will warn users that they are about to receive "tainted" inputs"? I believe for users like us, we know it's absolutely BULLSHIT, but that won't be the situation for newbies and normies who merely want to use Bitcoin for "coffee transactions".