Cox has a strict policy about no leaks concerning internet service upgrades until just a couple of days before the new service levels are available. If you get a full week(7 days=168 hours) of notice prior to an upgrade, consider yourself outstandingly lucky.
That being said, it appears to me that Cox is heading for a standardization of its internet speed offerings across all its market areas. 5/1, 25/5, 50/10, 150/20?, 150/25?, or 150/30? may be the final lineup for a national market with 8 downstream channel bonding and 4 upstream channel bonding. The price for each of those service levels may not be standardardized across the nation.
My wild guess for the outer limit of when this would happen would be Wednesday January 1 2020.

But Cox indicated on May 5, 2014 this: »
www.lightreading.com/cab ··· d/708919"As it prepares for its 1 Gig launches later in the year, Cox is already boosting the top broadband speeds it offers. At the Cable Show last week, Cox CTO Kevin Hart said the third largest US MSO is now increasing its fastest downstream speeds to 150 Mbit/s to 200 Mbit/s across its service footprint."
It would make logical sense to upgrade Irvine before offering Gigabit, but Cox can be anything but logical at times.
Non-wild guess is Sunday January 1, 2017.