I can agree and see most of his points except the guild one.
"In Classic, your guild is a big deal to create cohesion, but as WoW emphasized the solo experience more as time went on, that socialization element was lost"
I am curious how he thinks guilds have changed from classic to now. You still join a guild to raid, make dungeon groups easier/quicker, to pvp and even some leveling guilds. Basically exactly like classic. You still mostly solo to level(like classic). How was it lost? It's basically the same thing. Guilds are still a pretty big focus for players, except the ones that just dont care and will pug forever, again no different from classic. Unless he is just upset at more solo friendly activities on top of all the group stuff, things like WQs, pet battles or upcoming torghast.
I still find it odd blizzard has not given wow any kind of Guild House/zone or something. Unless they just don't want players sitting in their guild halls/house and making the major cities empty.