How Wasabi was "demixed" by Chainalysis
Channel: Samourai Wallet
Date: 23/02/2022

TLDR

The 25 BTC unmixed change went to the same address as a 0.401 BTC mixed output. User didn't do this address reuse, the client did. 

User likely had no idea that happened. They then spent that 0.401 BTC in a small consolidation of ~1.4 BTC to a Poloniex address.

More Info:
https://twitter.com/LaurentMT/status/1496252553075597318
https://twitter.com/SamouraiWallet/status/1496470477694709761