I think minor grievance gets upgraded to major grievance when it’s a leader of the company no longer engaging with you, effectively turning you into a pariah and unable to do your work leading to termination.
Allegedly. Out of 700+ employees?
We can assume that this happened way before there were 700+ employees.
High probability this “discriminatory language” is just someone having a hard time switching pronouns. Listing very minor grievances like this give the letter less weight than it otherwise could have.