Media relations manager Alan Jeffers confirmed the policy in an email to Dallas Voice:
ExxonMobil’s U.S. Equal Employment Opportunity and Harassment in the Workplace policies have been updated to include sexual orientation and gender identity, which is consistent with ExxonMobil’s long-standing practice of listing enumerated protected classes as defined by federal law.
ExxonMobil’s policies prohibit all forms of discrimination in any company workplace, anywhere in the world. ExxonMobil supports a work environment that values diversity and inclusion, and has numerous inclusive programs and policies that help make ExxonMobil a great place to work.
The link to the policies are available here.