I still remember the first volume of Nanbaka and how it debut on online manga sites. It had a lot positive feedback not just from the manga community but to manga critics as well. Often, a new manga don't get that much of a chance to be animated. It takes time and also recommendations about it but the content is never hard to crack though. I mean, comedy genre manga is super easy to be adapted into anime.
Would Nanbaka have a season two? Hmm, let's see. If the studio is going to get content from the serialized volumes then it might take some time before it gets another shot. The manga itself has a lot of content published already, it is just a matter of debate and sales from the higher ups if the studio would have a go signal on producing anime content for a second season.