The company announced that they want their users to feel comfortable on their platform by being their true authentic selves, which includes expressing their gender especially when it extends beyond the definition of just male and female.
“We collaborated with our Network of Support, a group of leading LGBT advocacy organizations, to offer an extensive list of gender identities that many people use to describe themselves. Moreover, people who select a custom gender will now have the ability to choose the pronoun they’d like to be referred to publicly — male (he/his), female (she/her) or neutral (they/their)”. - Facebook also announced in their post.
How do I change gender pronouns on Facebook?
Go to the Facebook website and log in to your account.
Click on the profile picture in the upper right corner.
Click on ‘About’.
Select ‘Contact and Basic Info’.
Click on the ‘Edit’ icon next to the gender icon.
When you select the ‘Custom’ option, Facebook will give you an option to select pronouns.