The main reason that they're not listed on the Blue Mage Hunting Grounds site is probably because they're not worth going in to Dangruf Wadi to try and fight solely for learning those spells. Those spells are relatively low level, so any Blu actively trying to learn spells would be going after Opo-Opos well before the 90's, and even if they were to wait till they hit 95 to learn them, there are still safer places to do it than in Dangruf Wadi on those particular Opo-opos. Could people go there? Sure, but it wouldn't be practical to when there are tons of weaker ones around that would still easily get the job done.
My thoughts and reviews
Lady Jinte wrote:
Vlorsutes' Negotiation Skill rises 0.2 points
Vlorsutes' Observant Parent Skill rises 0.3 points
Vlorsutes' Argument Diffusing Skill rises 0.1 points
on all sorts of sci-fi stuff...and things.