He has direct influence over some of the Okudagrams on TNG-R (which override the previous canon)
He has "direct influence" because he was hired to work on the production. That's all. He's a paid staffer making decisions that are limited to artistic and visual matters. He's not a studio executive dictating the direction of the franchise.
It's not like there's some master Star Trek
policy office at CBS handing down dictums that control canonical productions. Yes, CBS Consumer Products has a couple of employees whose job it is to oversee the tie-ins and make sure they stay consistent with canon, but you're mistaken if you think that the makers of actual screen productions are subject to similar oversight. The screen productions set the course of the franchise, and their makers decide for themselves what the continuity will be. The licensing people just make sure that folks like me follow that lead.
while Orci obviously used the conjectures to come up with dates like 2230 or 2233 in STXI.
Because he's a fan and he wanted
to. If he'd wanted to contradict those dates instead, Mike Okuda would've had no ability to stop him. Producers tell the art department what to do, not the other way around. And someone who was in the art department of a previous
production would have even less ability to influence decisions.
Before that, TOS-R had confirmed Greg Jein's conjectural registry number scheme, also adopted by Mike Okuda.
Again, that's because Mike was actually hired to work directly on that project and was paid to create those visual effects shots. He hasn't been paid to make decisions about the Abrams films.
I'm not saying his and Rick Sternbach's works are canon, only that it makes no sense to ignore them, since you never know how much of that will eventually become canon.
If you decide to exclude something without even considering it, that's ignoring it. But if you do consider it, take it into account, and decide that it's non-binding and unlikely to matter, that's not ignoring, it's making an informed choice. "We don't know it won't be canon someday" is a rather weak standard, and one that could become quite a straitjacket on the imagination.
And let's not forget, this is
all just imagination. Canon itself is not some absolute standard of truth -- it's fraught with massive inconsistencies and contradictions and mistakes, because it's made by a bunch of different people making different assumptions. Any attempt to craft the pretense of a consistent set of rules underlying it all requires glossing over a few details here and there. Bottom line, the conflict between the "Enterprise
Class" and "Constitution
Class" references in the movies is simply a mistake. We can try to make up imaginary fixes for the continuity error, but there's no explanation that's completely consistent, because it's really just an attempt to handwave an inconsistency. So whatever the case, we have to "ignore" -- or rather, make an informed choice to disregard -- something, somewhere. That's how handwaves work.
Why adhere to one interpretation when you're writing a tie-in novel and are bound by Okuda's conjectures, another when you're not?
When you go home from work, do you only do things that you're allowed to do in the office?
Besides, it's been quite a few years since the Chronology
were updated, so I don't think the old rule about following their lead is really in place anymore. These days Memory Alpha is probably considered the go-to reference. After all, the reason for respecting those sources is that at the time, their authors were
actually working on the shows and so it was possible that their ideas might end up in an episode someday -- although, as stated, many of their conjectures were instead contradicted, so that was simply about the licensing people hedging their bets. But now, the Okudas are no longer employed on Trek productions except
for the remastered home-video releases, so they're not as "close to canon" as they were. Sure, Orci or the Bad Robot people could draw on those books for reference, but they could also draw on any other tie-in, like the way they got Kirk's parents' first names from the novel Enterprise: The First Adventure
. And they're totally free to disregard them if they want.
There is no need to ignore evidence, canon, near-canon or only licensed.
Except that canon ignores the last two of those quite casually, and sometimes ignores the first as well.