Just to clarify:
-All iPhones have their software/firmware come directly from apple servers. Rogers has no control over this.
-Carrier Settings also come from Apple Servers, however Apple and Rogers communicate on what settings are enabled/frequiences, etc. But it's still pushed by Apple Servers to all iPhones (locked or unlocked)
So if you have two iPhones, one bought from a Apple Store unlocked, and one purchased from a Roger store locked/on contract, both have identical software/firmware and identical carrier setting files. Rogers blocks WiFi calling and VoLTE using the IMEI of the phone on the Rogers Side of the network.
The best way to get WiFi calling and VoLTE is to call Rogers and ask them to update your IMEI number on their account settings page, make sure they have the latest IMEI info for your current phone. Also on your WiFi Router make sure all VPN traffic is enabled, VoLTE/WiFi calling uses VPN to communicate to Rogers.