It's an interesting point... I suppose with some trans people their persona or their role in an institution/company is so big that it might be presumed they are publicly out when that is not the case.
Many, many years ago, on the cusp of my first attempt at transition, even though I was had just finished university I was on campus at a student political meeting (for reasons I can't remember) someone was speaking who I did not know - turns out they were a lecturer or something involving teaching. I was told they were a "transsexual" by one of the other students. I don't know why they shared that information with me as it wasn't relevant to what the person was talking about. Admittedly, being trans was a lot rarer in 1989 so I suppose that student felt it was "OK" to share that info. I presume it was common knowledge but I couldn't say. Common gossip more like, something that was really no one else's business was readily shared amongst everyone most likely.
Some months later, when I was intending on transitioning, I was hoping to speak to someone, anyone, who had been through the process (no internet then!) and since this person was the only one I knew of (mind you, I didn't know them, had never even been introduced) I was certainly looking to talk to them. One day, when I was back on campus I crossed paths with them and said hello, introduced myself and just launched into this shpiel of how I was trans and wanted to know if I could maybe talk with them about "what was involved". They were probably too stunned or too polite to tell me to "get stuffed" and agreed to a meeting - we set the time and place but then they never showed. It was at their university office (in those days no email or anything) and I left a message hoping to hear from them but, surprise, surprise, never did.

I think that kind of answered my question about how they felt about their status being "common knowledge"...