Are you saying that RBC has no legal right to restrict speech in the work place?
Every company has some power to limit free expression in the workplace as it pertains to managing work. To force any individual to voice support of a political principle which they don't agree with is begging for trouble though.
Restricting speech is one thing. Demanding that a person speak in a particular way is another. Unusual emphasis on voluntariness is often a sign that you are being "voluntold."