>>281112118Volume 16 (part 2 of 15) is still the latest one. Since then the only new thing we got from Maruyama is a sidestory about Ainz again NTRing another man's wife, this time intentionally (he cast Dominate Undead on a Ghost Ship who is a wife of her Elder Lich captain). I think it's a bonus for the cinema release of the Holy Kingdom movie.
I think they are still making that Overlord gacha, but my cursory glance of its story summary leads me to believe Maruyama's involvement in it is minimal, whatever the studio might say. I of course might be wrong but for all his faults, I don't think he is that much of a hack.