The engines bought by Morgan are "off the shelf" BMW units and as you cannot buy a BMW without A/C I can see why it is there. Removing it would be a waste of time and money and require a custom serpentine belt...
If the heater box also has the A/C matrix in it and the wiring loom has the necessary parts then any competent BMW specialist could do the job but if the A/C enabled heater box is not the same as the heater only box then it could be an expensive project.

Peter,
66, 2016 Porsche Boxster S
No longer driving Tarka, the 2014 Plus 8...