So, you do agree with me that input/output collaboration in coinjoin worsens its anonymity set?
No, it's the opposite: Having participants who remix before or after your coinjoin increases your anonymity set.
Everybody knows that except from Wasabi team apparently,
Wait, you don't know about the address reuse by the Samourai team?
as the transaction I linked was a coinjoin round, not a regular wherein an individual spends their coins.
You shouldn't reuse your addresses for coinjoin transactions either.
Isn't it possible to reveal common ownership in Wasabi by consolidating all your coinjoined coins in a single transaction?
Yes, you can consolidate your private coins and spend them outside of a coinjoin transaction if you wish to. There's an arbitrary warning if you try to consolidate 10 or more UTXOs, but I personally don't think it matters.
How could I know which Coinbase address you withdrew from based on which Coinbase address you deposited to? If this tracking is trivial like you claim, I would love to know how it's performed.
You either address a company like Chainalysis or you find them leaked in some darknet website. I don't know the precise procedure, but I can guess it is trivial if you have the time and money.
Okay so you were bluffing then since it's not "trivial" to trace someone's Coinbase withdrawal like it is to trace Whirlpool transactions which can be done with just a Bitcoin node.