Interesting article, and I stand corrected.
The subject came up yesterday on Fox News Sunday. Chris Wallace asked if this wasn’t perhaps a “solution looking for a problem”. The other panelists agreed, and one had interviewed several police officers, who said they could not recall any reports of this type of incidents. Wallace asked if anyone had heard of such an incident - they all shook their heads. Another panelist suggested the number of MTF transsexuals is extremely small, and those who would be interested in using their protected status to enter a ladies room must be negligible.
Then they all agreed, democrat and republican alike, that the question was likely being raised in the politically charged republican primary season in an attempt to create a “wedge” issue.
I realize I’m getting all my information from a single source, but I can honestly say that until I read the article you linked, I have never once heard of this issue being raised, other than as a hypothetical scenario.