Your "collateral rule" is ridiculous.  If "everyone else's beliefs" must always be considered and must never be or seem to be challenged then everyone is frozen, no one may ever act because someone, somewhere will be offended.
We are not robots.

Of course there are limits to "be your authentic self."  That would include, for example, actions of pedophiles, murders, thieves, liars, etc.  I would also include people who make fun of others beliefs, treat people rudely, measure people's worth by a single characteristic such as skin color, ethnicity, sexual orientation.  But that is just me. 

Someone who recognizes that he is gay and admits it to others is not offending anyone by his admission.  He is  presenting his own feelings, beliefs, and opinions.   The receiver may react but that reaction belongs to receiver.  The two may agree to discuss the issue or either one may decline, especially if it appears that hanging around to debate the issue is not going to be worth the effort.