I keep seeing "just use a resource pack" as an excuse for anyone who complains about the update, yet none of the people who use it seem to understand how ironic of a statement it is.
It's not an excuse, and it's certainly not ironic.
We have absolutely no idea if these will be in any "final version" or not. Everything might change, or nothing might change; nobody knows. So complaining pre-emptively is pretty futile. If some new textures come out, and you hate them, you always have the option of resource packs - why is that "ironic"? It's just fact. People have different tastes; some might like the new textures, some might hate them. The fact is, if you do hate them, you can get rid of them.
I think I'm gonna ignore all discussion of textures until there's a snapshot, and see what that brings.
Completely fake news. Just because some random people on reddit say something does not make it true.
Mojang have stated numerous times that they are continuing to support and develop java Minecraft. You can even see it happening; in the past few days, there's been lots of discussion about the new block-ID system and the work on textures for 1.13,
Even in the "better together" announcement itself;
"So going forward, the edition you'll find on Xbox One, Nintendo Switch, mobile and VR will simply be known as 'Minecraft', a separate entity from 'Minecraft: Java Edition', which is the original PC game (that we'll continue to support, of course)." 
The Meaning of Life, the Universe, and Everything.
Mojang have very recently indicated that they are 'reviewing' the textures, and from the discussions, it seems likely they will be changing most/all Minecraft textures to a higher resolution, as well as tweaking them.
Although they haven't said it, I suspect it will become part of the 1.13 update, which is already billed as a "technical update", ie changing and optimising code rather than new mobs/biomes/blocks.
I think it is unlikely that we will get 1.13 until early next year.
In general, I think updating the textures will be a very good thing. There will no doubt be certain things that people absolutely hate.... there will be fierce resistance to change. But we'll get used to it. There's no reason why people can't just use the old ones as a resource pack. (It would be nice if Mojang chose to include the old textures as a pack, along with this update) But that will not stop the internet, and this forum, from going into a flame-overdrive.
I basically think it's a great thing. It will have a huge impact.... much more than any other type of update (new mobs, new bosses, etc because it so drastically affects the appearance of the game.
Caveats: A lot of the above is opinion/speculation. All we know for sure is, Mojang say they're gonna review the textures. I have no idea whether any changes (if any) will form part of 1.13 or not.