I think that privacy will be improved even more when Taproot goes mainnet for Bitcoin in few months, so my question is will ChipMixer also benefit from this?\
No. Taproot primarily benefits scripting whereby not all of the possible spending conditions are fulfilled and specifically, Schnorr signatures allows for PK aggregation.
Neither of those are current ChipMixer's usecase, where the private keys are prepared before the user initiates a session and the addresses are normal P2PKH or P2WPKH.