Timeline-change theories are on thin ice because it only takes a flashback from DSC/SNW/PIC to see the ENT era in Disco style also. They’re just not going to recreate Zimmerman’s production design or Foundation/Eden VFX if they can fancy it up to better fit DSC. You know, take a Disco-era bridge you have, redecorate it and come up with something along those lines, but not an actual restoration.
As opposed to TNG and DS9 and VOY and ENT where they painstakingly recreated (not perfectly, but darn close) the TOS and TUC era sets accurately without throwing in their own style. (Even the Kelvinverse showed accurate Prime universe imagery where applicable).
That's a huge part of the issue here. The 90s Trek shows were happy to go their own directions, but in terms of respecting their in-universe and BTS histories, they went the extra mile to NOT change things, thus establishing the franchise standard of how the franchise treats itself, which is now no longer the norm. But the new norm is in contrast of the entire rest of the history of Trek.
And that's fine, it's doing its own thing. But it should be no surprise that it is jarring to people who like and are accustomed to a respectful way of doing things. Until DSC, there was a code of "if you don't want to show another Trek era in the way it already appeared, then don't show it, do something else" and even 2009 went that way: if it's going to be completely different, it's a different universe now. And no, changing makeup of Klingons or Andorians is not the same thing. The Enterprise Exterior and Interior are stars of the show as much as any of the leads, not special guests of the week.
Edited to add: (And no, changing them as they move forward in time in-universe isn't a reboot nor is it disrespecting what came before if the before remains unchanged. TMP changed everything, but it did not sit in contrast to TOS as it moved it forward, and with enough believability that it
could be the same ship with explicitly in-universe changes. TOS to TMP is a different beast altogether anyway as it was almost incomprehensible that any large group of people would hold them up next to each other, at that point as far as the creators were concerned, TOS was a thing of the past, not part of the new world of on-demand streaming, etc. The modern, connected world, if anything makes fidelity to the source material
more essential not less, unless it is explicitly a new version, which the creators and marketing have decisively argued is not the case.)
