With the switch from gas to renewable electricity, will domestic electric consumer units have to be uprated in respect of supply ampage?

You will only need single phase electric supply up to 28kWth heat pump. Depending on how full the distribution board is in your house, you may need an upgrade. It is a question to ask your installer and/or surveyor. The installer is also responsible for the Connect and Notify process with the DNO, who will advise if there are local issues with electrical connections.