i have this pet theory that it was inspired by BitchX (they prominently mention being like IRC)

Probably on purpose. Like "Broken, But Whole"

It could be deliberate. Like Wechat's Chinese name is "Weixin", which is a pun on "for sex" in Mandarin (for which its "people nearby" feature originally saw heavy usage). As a decentralized social network, Bitchat might see similar usage.