Even if this game was touted as some 1000 hour experience (I would like to see this) no one in their right mind is going to play a game, maybe aside a mmorpg, for 1000s of hours. These arpg are seasonal games, meaning that most people will jump on a brand new fresh season and play it until they get bored again. For some it might be 20 hours and others it might be 100. But most end up quitting and waiting for the next season or take time off and wait a few seasons between trying it again.
These games are not live service games like Destiny or others like it. These games are seasonal and I would still like to see this 1000 hour promise that blizzard made you.