The Constitution has built-in mechanism for changing form of government, but not zure to what degree.
I believe most people who take the Oath don’t really think about it. They should.
The other thing is, Oaths have not been an absolute defining entity for the legitimacy of government.
Anyway, it’s past time to give due diligence.
https://youtu.be/e9783wUHcu4?feature=shared
“Oaths have not been an absolute defining entity for the legitimacy of government.”
That wasn’t the question. Question was if it violates the oath.
“Can a public official advocate for a form of government other than a Constitutional Republic without violating his/her Oath of Office?”
Advocating for a non-Constitutional form of government clearly violates the oath to preserve, protect and defend the Constitution.