Having had the chance to test the new talent arrangement of Destruction, the spec is in a very good place. However, I would like to make a few suggestions, one of which has been echoed above (from the perspective of a more Mythic+ player):
1.) I absolutely love Dimensional Rift (DR) and am overjoyed it is here to stay. At the moment, though, it feels considerably undertuned. Currently in DF (with the four set) Immolate has a chance to refresh a charge of DR, which occurs often when more than one target is dotted with Immolate. In the beta the refresh condition is tied to casts of Incinerate, which, in the majority of beta Destruction builds I have tried, is (comparatively speaking) infrequently used, thereby greatly lowering the probability of a DR charge refresh. The easy solution to this problem is simply to let Immolate instead have a chance to reset a DR charge. This would also sync very well with Unstable Rifts, since, of course, the more rifts one has, the higher the AoE damage. As has been noted above, Dimension Ripper is either bugged or has a freakishly low proc rate, as it has not activated for me even once. Immolate should replace Incinerate here in the capacity of refreshing a DR charge.
2.) I personally believe it is both a tragedy and a mistake not to reimplement Flame Rift into the talent tree. It is very iconic for Destruction and quite powerful. It should be baseline to Dimension Rift itself, albeit with a lower occurrence rate compared to the other three types of rift (as it works now and as it did in Legion). I do not see any reason why it should not carry over into TTW and beyond. Another strategy for its reimplementation could be making Dimension Ripper baseline to the Dimensional Rift talent itself and replacing it with Flame Rift as a capstone. I was disappointed to see it added to the tree and then removed again, seemingly without justification.
3.) Avatar of Destruction is a superb talent that adds a lot of power and flavour to the spec. It seems more geared to single target, though it is certainly useful in AoE (helping to generate Soul Shards for more Rain of Fire casts). In order to further diversify and expand Destruction’s AoE toolkit, however, I would really like to see it put on a choice node that summons a different demon (or the same one, with perhaps a different color scheme) that casts Cataclysms on its primary target. Such a choice node would mirror that seen in the Demonology tree between Mark of Shatug and Mark of F’harg, the fundamental distinction between which is clearly one of ST vs AoE, respectively. Cataclysm as a talent, I fear, will not see much use (outside of ST, since we are forced to choose it to get to Scalding Flames and Channel Demonfire) in TWW, unless one is playing the Hellcaller hero talent tree (though, even then, it has a frustrating 30 sec CD). I recall reading in the Alpha stage that Blizz had planned to make Cataclysm a more attractive choice, but not much was done to that end, in my opinion (Inferno is still stronger in most cases). Having an Overfiend cast Cataclysm regularly when Ritual of Doom triggers would allow for consistent, efficient multi-dotting of mobs, which can otherwise be achieved less efficiently only through one-by-one dotting or Cataclysm on an inconvenient 30 sec CD. This would help alleviate the burden on Hellcaller Destruction warlocks to keep Immolate (Wither) on as many targets as possible (and make Channel Demonfire even more potent and relevant, as it can sometimes feel out-of-the-way). If talented, Dimensional Rift and Unstable Rifts would likewise gain a major bonus from this, since numerous active Immolates would reliably generate DR charge refreshes. Rain of Fire is strong, but continuously pressing it again and again without the burst of Cataclysm doesn’t feel that great. Cataclysm is one of my favourite abilities, and feeling as though I cannot pick it (especially when playing Diabolist) is a bummer.