Not trying to exclude it but ESO is apart of the...

A-series: A number of objects or events arranged or coming one after the other in succession.

But not apart of the...

B-series: A group of objects related by linearly varying successive differences in form or configuration.

That's why it isn't considered ES 6. That's why Blades and Legends isn't considered apart of the linear series of games (in this particular definition) like TES 4 or TES 5.

Also I didn't mean to exclude ESO from the A-Series or from the franchise at all. I actually love ESO and play it. That's why I know about the Ash'abah. The context of me saying "never before seen" followed by pointing out that ESO isn't apart of the series is because it wasn't seen or heard of to my knowledge apart of THAT B-series.

I didn't mean to disrespect my ESO brothers and sisters or the entire Elder Scrolls family. It was just meant to clarify that Ash'abah was apart of A-series and not B-series.