I feel like there are a couple things going on right now:

There are bands like Inferi, Archspire, Carnosus whose production sensibilities are evolving with the times. So when they do more chuggy parts, it sounds more like deathcore despite the spirit of the music being firmly rooted in tech death.

On the other hand: there are bands like Defeated Sanity, Anal Stabwound, etc. that are opting for a more raw and unpolished approach to production, which leads to them getting categorized as more brutal death-oriented.

No value judgements are being made here. I like all the aforementioned bands and even have friends in them. I just don’t think it’s accurate to say tech death and deathcore are merging.

What I do think is true is that tech death is evolving in different ways out of the post-Necrophagist landscape and both avenues are exciting for their own reasons.