With the complete lack of communication from the dev team, Data Mining the PTR could be extremely useful of late. We have no idea of the changes that have taken place on 3 PTR patches in a row. So a datamine would at least give us a idea of the direction they are taking with this patch in lieu of them actually telling us..
Datamining isn't magic. They can't datamine info if theres no data. There was a datamining for 2.5 and thats all.
About the Diablofans state: diablo is bit different than overwpn or heroesnexus. First of all DFans is much older and was actually acquired by curse. If i understand correctly person who was writing stuff for overpwn decided to stop doing this, so they decided to shut it down. The problem with overpwn and heroes was that there is not much of a content to generate on those except just a gameplay videos. DFans is more like heartpwn with all the builds section, that means people will come back here to check those builds every time new season start and even during the season (to check what changed or check builds for other classes), this is in my opinion reason why is DFans still running.