Since I haven't been involved with Bitcoin for a long time, I have no idea about the current technical circumstances, but I came across an article reporting that Arkham Intelligence has developed algorithms and patterns to completely deanonymize transactions, even Coinjoins.
Can anyone tell me if this is true and what the current technical status is?
It's rubbish.
If any of that was true then they would have been contracted by the FBI to deanonymize Whirlpool transactions from Samourai Wallet, and as far as I know, no deanonymization has been performed yet.
Simple, single-transaction coinjoins with a small UTXO set can be deenonymized, but not any types that are used in practice.