You're literally the only person I know that thinks Pestilence has gone back to playing music that resembles their earlier output in any form, so lol.
Putting it more simply, I believe the term tech-death as broadly used should be split into four categories...
1) Old-school tech/prog-death, consisting of albums that predominantly feature death metal riffs, with little or no obvious influence from any of the major tech-thrash acts (examples: The Erosion of Sanity, Nespithe, the first two At the Gates albums, the first two Atrocity albums, maybe Cadaver's ...In Pains, parts of Deicide's Legion)
2) Old-school tech/prog-"death", consisting of albums that may feature death metal vocals and may have come from a scene generally associated with death metal, but feature an equal or greater amount of thrash riffs and otherwise take after death metal in little more than tuning and certain aesthetic qualities (the first two Atheist albums, Cynic's demo material, Thresholds, Spheres, the first Hieronymus Bosch album, a lot of post-Spiritual Healing Death)
3) Progressive alt-extreme metal, consisting of albums that once played death metal or grindcore, usually of a progressive variant, but stripping away most/any distinguishable death metal characteristics, usually in favor of non-metal influences (Focus, Pleasuredome, Disharmonization, mid/late-90s Sadist)
4) New-school tech/prog-death, basically beginning with the Suffocation sound and going from there as bands began incorporating a high amount of blasting, sweep-picking, further down-tuning, some tech-y breakdowns, etc (Spawn of Possession, Cryptopsy, Origin, Necrophagist, blahblahblah)
Now, granted, that doesn't fully cover every band or album, and there is some stuff that skirts the border of two or more, but it seems pretty obvious to me that the tech-death of today has little semblance of the early stuff that is usually most heavily praised, with the exception of the occasional Gory Blister or whatever rehashing Individual Thought Patterns. To say "wtf man? My homies in Spawn of Possession are still keeping it sweep" is basically as meaningful as pointing to groove metal in the middle of the 90s as proof of thrash's continued existence.
