[2018] Path of Exile will last at least another 20 years, confirmed by Chris.

Traditionally, in English, witch is also unisex - some men were burned as witches, although fewer than women. Witchcraft was a name applied to a variety of traditional spiritual and religous practices that Christianity didn't like at various times, and they had both male and female practitioners.

Warlock means "betrayer", and it being considered a male equivalent of witch comes from Scots, and has only relatively recently become a popular English meaning.

To continue the random aside train, as an English speaker, Scots is a weird language to listen to - at times seeming like a dialect of English and at other times like a totally different language. This video is a cool quick introduction to the topic, and the description has a link to a speech given in Scots, and it's really cool to listen to.

EDIT: I am not making any statements or implications about potential future PoE content in this post. I'm just chiming in on a conversation about language with some stuff I find interesting.

My knowledge here comes primarily from research I did for a project in high school, combined with a general interest in both languages/etymology and the historical concept of/belief in magic, not from my work at GGG. All the classes except the Shadow and Scion were named before I joined the company.