Even if sent using P2TR inputs, if sent to a bc1q address, it will be P2WPKH, and if bc1p, payments sent to that address will be P2TR outputs. I'm not sure anything needs to be done by the receiver to receive payments with P2TR inputs.
Also, there's a PR where devs are still working on MuSig2, which would be of interest to River, but I don't think it's finished yet.