I can't speak for Bo specifically, but I would assume what Bo was trying to highlight, is that for anyone that was playing back in Beta, or even those playing just 5 years ago. The game feels night and day different. And nothing about whether it's received any updates or not (I don't quite understand what you were trying to get at with that comment, very weird, baffles me even what you were trying to get at). And not from a mechanics level, as that's obvious given it gets new mechanics added every 13 weeks (assuming they go core, which most eventually do in some capacity eventually, even if not initially). But from a engine prospective, it's had several overhauls, or just progressive updates trying to improve how it's networking, how it functions, how it feels and how it looks. So in that regard it's nothing like it was 10 years ago.
As for it feeling dated, probably most of what of you are identifying with there is probably intentional for the most part. In that it's trying to capture a specific audience that enjoyed ARPG's from back in the late 90's, early 2000's era of ARPG's, while trying fix what they believe were some of bad parts of ARPG's from that era. Part of that is obviously them trying to also capture a new audience, as it's not like those games don't exist still if you want those games you can still play those games. Now whether they captured that or not, is in the eye of the beholder. And if it's not, then good thing we don't just have a couple of options.