Looking at Picard season 2, whereBecause they share the same past:
- any person or thing that is already born/exists before 2233, has to be identical in both timelines up to 2233. E.g. if AbramsKhan has miracle blood, so has the real Khan, since Khan was born in the 20th Century.
- especially all of ENT is the past of AbramsVerse, too. E.g. Jonathan Archer is born 2112. So, if AbramsScotty experiments with his beagle in Abrams2250s, Archer will have been ~140 years old at that time. Also, the NX-326 (as given by Abrams) is launched before the NX-01 (as given by canon). Anything in AbramsTrek that contradicts ENT is/would be a canon violation;
- all the astronomical settings are the same (regarding distances and so on; not including blowing up planets), e.g. if Vulcan has no moon in prime universe, then AbramsVulcan does not have any moon, too, and the distance from Qu'noS to Earth is the same in both universes - otherwise: canon violation.
- The setup in the movie at January 2233 shows things that have to be in the prime universe, too. E.g. if there is the survey vessel USS Kelvin with 800 crew members in January 2233 of the Abramsverse, then there is the same ship in the prime timeline where even the flagship only has 400 crew.
So, just saying "divergent timeline" and then thinking that nothing at all can be a canon violation, is very obviously wrong.
But yeah, I think it is quite clear that the authors and creators of Abramsverse are no "big thinkers", they brainstorm an idea and if they like something, then they don't even take a second look on the idea, just do it without considering anything about it.
Just from looking at the plot of the movie one can say: If they can't even put any thought on making the plot somewhat logical and believable, it is clear these people also won't be able to make something consistent to existing canon.
Adhering to canon does not automatically make a good movie/story. But "adhering to canon" and "editing the plot of a movie/episode in a way that it is in itself coherent, logical and believable" require very similar skills.
Guinan didn't know Picard because since the future had changed, the past of "Time's Arrow" had too
Also, IRL it's a reboot and all that was a handwave.