It’s seems to be finished now (according to my baka updates investigation) https://www.mangaupdates.com/series.html?id=136653 :(
It seem that it was the announcement for vol 2, the next page is preview and it in vol 2. So yes, it's really end now
Yeah, i figured as much based on the pages that followed I was hoping there would be another extra or volume tho
* by the way, by "they" I meant the publishers and not the scanlators
Sequel like legit sequel? Or did they label volume 2 as "sequel"?