Merging your post mix coins can create a near deterministic link since the input amounts vary (easy to do if you're using the wallet for mixing before sending on to cold storage)
Discussion
I can only thing of one instance in which merging post mix coins could create a near deterministic link, which would be if you sent a single UTXO to an empty wallet, coinjoined for a single round, then swept the resulting UTXOs to cold storage.
This edge case correlation is prevented if you register a second UTXO (especially if the second UTXO is already private), remix any UTXO from the first round, or merge your coins in two separate transactions when spending.
True, but that seems like a fairly likely usage pattern for those using Wasabi purely as an intermediate mixing wallet