After 20-30 mixes recombining them from all sorts of utxos shouldn't be that easily identifiable. Not even the amount will match anymore after so many fees.
This doesn't scale, since new entrants to Whirlpool pay the mining fees to remix the existing liquidity. This means in order for one user to get to 10 mixes, that would require 5 different users to stop at one mix (with a 5 input / 5 output structure).
After 20-30 mixes recombining them from all sorts of utxos shouldn't be that easily identifiable. Not even the amount will match anymore after so many fees.