It seems that this has been changed quite a long time ago, there are only territory control alerts and I have not seen one bio-lab, tech plant or amp station capture alert since...hell, maybe over a year ago? I wouldn't doubt that I missed something in one particular game maintenance/update thread. Iv'e been googling up about this and for some reason I can't find anything, there has to be a thread or website that shows something about this, there can't be none. Anybody know why these alerts simply just... vapourized? Thanks.
Not enough pop to make those sustainable. It ended up just being random ghostcapping on an empty continent which would decide the alert. The current one saturates a single continent, allowing for bigger fights to develop.
The cross-continent alerts never made any sense anyway. It is either ignored by all but one faction, or spread the population frustratingly thin to the point that I would rather log out and come back later. All in all, I'd say it's a good riddance. And to answer your question, they were gone around the time continent locking via alerts was implemented.
On Emerald, during primetime... we have people complaining about 40 minute non-member queues for swapping continents, after which they are frequently booted to other continents when attempting to redeploy / respawn (Thank to the shenanigans / bugs going on with deploy changes) - Multi continent alerts would exacerbate the issue to a significant degree.