The full interview is worth a watch/listen:
https://www.youtube.com/watch?v=p12F5la-yPo
There are some eyebrow raising moments. In one (timestamp 29:01), Holly Longdale quotes Metzen:
There are also one or two times when Ion insists that Blizzard has accelerated the pace of development while "maintaining quality," which is laughable given the state of 12.0.
The interview is full of references to how Blizzard is analyzing player behavior, "reacting to the community," players getting older, players wanting to play with their kids/spouse, accessibility, content being released that is overwhelmingly popular despite the initial backlash (delves/housing), etc., and it all kind of points in the same direction.
Blizzard seems to have determined that the path forward (i.e. where the $ is) for retail is to take a 90 degree turn and devote the bulk of their resources to the casual player base, regardless of their long history of neglecting casuals in favor of the M+/raids/e-sports loot grinder.
The players Blizzard is suddenly catering to now aren't really interested in the seasonal loot grinds of the past, particularly the ilvl-chasing PVE modes that have been the focus for the past 10 years, yet Blizzard can't stop themselves from implementing every
new feature as a seasonal loot grind, including delves and housing. Blizz is too attached to any system that they think drives engagement and that mindset will prevent them from delivering any other experience.