The phenomenon you describe is not new. Discrimination law differs by jurisdiction, but there are various protected classes that may be seen as "optional things people choose". People will not agree on precisely which such classes truly reflect choice, but some examples may include religion, familial/marital status (and related), political activity/affiliation (and related), pregnancy (and related), military/veteran status, matriculation/student status, place of residence/business, whistleblowing ("anti-retaliation"), source of income, smoking, and participation in lawful activities during non-work hours. (Some people believe even more class membership reflects choice; indeed, this is often a factor in their reasoning about whether the classes should be protected.)

Some of these classes are protected in the United States as of the Civil rights acts of 1964 and 1968, as well as other federal laws from 1974 and 1978. (The protection of different religions is, of course, a founding principle of the United States. However, many people do not believe religion is a choice.)

The following webpage was helpful in assembling this list and includes a few amusing items such as membership in the Communist party (not protected in Nebraska) as well as having a degree in theology (protected in Oregon): http://www.ncsl.org/research/labor-and-employment/discrimina...