This is just... silly.
I understand why CRZs were implemented. Personally, I don't like them. I don't think they are necessary. But I do understand the reasoning behind them. But they didn't think things through. This is what de-bugging, alpha and beta versions, and PTRs are supposed to be for. So you can catch these issues and resolve them BEFORE pushing them to live servers.
100 people who posted before me have made this point already, but I am going to add my voice to the chorus. Once you discovered this issue exists, who's bright idea was it to disable the working functions (timed world events) instead of disabling the 'not-ready-for-primetime' feature (Cross-Realm Zones)?
Blizzard is usually very good about not going live with something until it's been thoroughly vetted, almost to a point of obsession. So most players are understandably surprised and annoyed when you so colossally drop the ball they way you apparently have with CRZ and it's very predictable effect on timed world events. It's so not like you guys to fail like this, we're all stunned when it happens. And this... non-solution solution is also not the typical way we are used to seeing Blizzard handle things. People are understandably frustrated.
Okay, I'm done ranting. Now it's solution time. Without having a complete understanding of how everything works on the back-end, all we front-end users can do, is offer common-sense solutions. Here are mine.
1. One thing I do not understand, is why there is shared iteration of Elder Clearwater and Riggle Bassbait across multiple servers. Having to complete across servers for the quest fish is...annoying, but I could learn to live with it. If it is just too much trouble to have a realm-unique NPC in a CRZ, then just take Booty Bay and Dalaran off the list of CRZs. Ultimately, there is no valid reason why there should not be one Tournament winner and one Extravaganza winner per server, period.
2. Another thing I've often wondered, is why there isn't a single time zone for all US servers (and one for all EU, one for all Latin, etc), regardless of what the time zone is in whatever data center the servers physically live in. Set all US servers to CST (to split the difference between Pacific and Eastern) period. Make all EU servers run on Greenwich time, and so on and so forth. Dungeons, Raids, and Battlegrounds are something else altogether. I play on a server in EST, but whenever I enter an instance, my server clock...changes. As if the instance is in a different time zone than my server is. Set them all to the same time. Simple.
3. This one has little to do with the timed world event issue, but it is nevertheless a CRZ issue that many folks have been lamenting, so I'm adding it to my list. CRZs, if you are going to insist of having them, need to be fully restricted by server type. PvP and PvE obviously don't mix. But to those folks who chose to play on RP servers and the reasons they did so, you must recognize why RP and non-RP also doesn't mix, otherwise you might as well just scrap the whole idea of separate servers for the minority of players who seek RP immersion. Now, we understand that there are significantly fewer RP-PvP servers than the other types, but if you CRZ just those together (and just the RP-PvE types together), it will still be better than it was before, at least in terms of the dubious reasoning behind CRZs. Those who rolled on RP or RP-PvP knew going in that they were going to have population issues. They accepted that as the price to be paid for not having to play with people with names like 'Fartwizard'. Trust me, they aren't going to complain because CRZ was less effective for them.