Don't forget that better gear is available elsewhere also, so people are still going to gear up further and +15 is going to feel like current +12.
But yeah the harder the content is, organizing a group and making friends has always been encouraged. That goes for dungeons too now that they provide a challenge.
Base loot is up as well in case anybody was wondering.
13 = 875
14 = 880
15 = 885
Which is great, because some classes have terrible relics and trinkets from NH.
Boomkin treants are very helpful against Necrotic (and Raging).
Actually happy they did this change because for the first time we pushed for a 15
Cleared our 15 Raging/Necrotic/Fort Vault
In time