aren’t “waifu” and “husbando” gairaigo words used extremely informally, e.g. on the Japanese net?

Sure, but what does that mean in the context of western, non-japanese people using it in their english conversations, many of whom don’t speak Japanese? Why type out the Japanese pronounciation of english words? I’ve only seen it ever, in one way or another, make a joke out of the pronunciation of that word, so no matter where it entered into popularity it is still just “wife” and “husband” with a racist accent.