Guys technically the manga is the one who deviates. Both WN and LN tells the story of the classmates side by side with Kumoko's side, and now the anime does too.
Chapters like this make me keep coming back to this manga. It's such in an interesting sight to see a 'monster' MC interacting with otherworld humans in such a manner. Hope we'll keep getting these goofy kinds of encounters more before MC actually gets to a level where they can just talk like normal humans.
The anime is actually a much better adaptation than the manga lol. The human scenes were included in both the LN and WN so the anime's being pretty faithful to the original source.