Many series have a bible which establishes certain basic ideas and propositions people want to pin down for the writers to nominally adhere to.
Star Trek may not have had a bible but it could with a little good will be described as "almost coherent"
There are a few basic changes like the Klingon makeup change and the retcon of the Ferengi that didn't cause major problems.
ToS had quite a few bits that didn't add up or features that changed from one episode to the next.
TNG was fairly consistent on its own.
The ToS movies didn't introduce major changes.
DS9 challenged a few ideas and while it did put the Federation's lofty ideals before a number of "damned if you do/don't" problems, it didn't try to make any substantial changes.
Voyager attempted to marry the exploration of TNG with the drama of DS9 until they declawed that idea, but again fairly consistent.
Enterprise is probably the series where writers were first really tempted to openly retcon established on screen canon. There were a few "submarines" like not specifically identifying a race to avoid their established first contact being upset etc.
I'm withholding judgement on Discovery for the reason that until now it has heavily been implied that some dimensional travel is involved and that there is a real possibility that the future of the series might be more fluid than previously thought combined with a less than stellar fan reaction.
Until now Discovery seems to have been quite keen to retcon many details of what was previously Star Trek canon. Is this part of a planned misdirection and surprise or are they only interested in the Star Trek name to push their own style of SF.
I have this hunch that the characters may not be from the actual mainstream Star Trek universe or are part of a larger reality which contains everything we have seen in the original Trek run and might even include the Abramsverse Trek … Maybe they discover they are already an amalgamation of different universes, and perhaps I read too much in this and they were simply doing their own thing under the Trek name.
We'll know when the season ends next year and what the future holds.