Star Trek fans have an odd need for absolutes in storytelling. "The Eugenics Wars happened on X date, here's the entry in the Star Trek Chronology, cross-referenced with the Star Trek Encyclopedia and the Greg Cox novel series!"
But Strange New Worlds is being very deliberate in that they've left the option open for fans to treat it as a separate timeline should they want to, but they won't ever explicitly say so. Later in season two, "Those Old Scientists" crosses Lower Decks, explicitly tied into TOS-TNG-DS9-VOY-ENT, with Strange New Worlds and... it's treated as if everything is fine and as it should be (with the exception of Spock, and that is played as him going through something never put into his logs). So it's left up to the individual viewer to decide with no wrong answer and I'm not sure Trekkies are good with ambiguity
I suppose with observers from the Relatively and guys like Daniels, all significant timelime shifts just get shifted back eventually. It's just a matter of time.
Things like Khan's birthdate change is just like a temporal yo-yo. Even the Kelvin Timelime may only have a limited lifespan.(if they don't make anymore films, it might as well have been rendered defunct)
Even Sera from that SNW episode (you know, if you've seen it) said the timelime always wants to heal itself back to the way it was.
Temporal Investigations: Admiral Picard, do you have ANY idea how much damage your leaving Cristobal Rios in the 21st century did to the timeline and almost destroyed the existence of the Federation?
Picard: What do you mean? Guinan told me that he got laid with that local lady and died smoking a cigar.
Temporal Investigations: We told her to tell you that until we were ready to reveal the truth to you. I guess we might as well tell you now...
(21st century)
Rios: Hey, you said your name was Khan? Say, you wouldn't, uh, happen to be genetically engineered or anything? (to himself: Should I kill this guy now and save everyone the trouble? And why can't I remember clearly if Khan was supposed to be around now or in the 1990s?)
Khan: Yep, I have superior ability. Watch me jump down this rooftop with no injury at all!
Rios: What no wait! (Khan jumps off a roof in an overestimation of his augment abilities and promptly dies)
Teresa: He's dead Cris.
(Temporal Investigations Agent beams in)
DTI Agent: You IDIOT! We are now ordering you Captain Rios to use the 'Gabriel Bell' method to restore the timeline. You are now Khan Noonien Singh and we are currently injecting you with augment enhancements. You now need to spend the next decade or so taking over a quarter of the world, starting a Eugenics war to kill millions, and escape with other augments on the Botany Bay. You remember your Kirk studies from the Academy? You need to try to hijack the Enterprise, **** their historian, get marooned on Ceti Alpha 5 for over 15 years, put worms in Chekov's ear, steal the Genesis Project, and kill Spock. We are also sending you separate instructions in case another temporal distortion has you woken up by some guy called Admiral Marcus instead.
Rios: Wait what? No no no...
DTI Agent: Also you and Teresa better start getting into bed and producing a kid who will become the ancestor of La'an Noonien Singh.
Teresa:
DTI Agent: Ok we've injected you with augment genes and given you Khan's identity papers move along, you have a lot of acting work to get started on, not to mention brushing up on your Academy history studies so you can accurately recreate Khan's battles with Kirk.
Rios: No no no... I made a mistake ever staying in this century!!!!
