Mexico Plan for Mobile Share Value - May 20, 2016
This looks like PART of the new plan announced for May 20, 2016.
At least the part for 15GB or higher Mobile Share Value plans.
"When you choose a new 15GB or higher Mobile Share Value® plan, you will be able to place unlimited calls, send unlimited texts, and access your Mobile Share Value plan data in Mexico like you do in the U.S.—with no roaming charges"
They have a business version of the page too.
It keeps saying "When you choose a new 15GB or higher Mobile Share Value Plan"...
Although the fine print says existing plans, it still has bits of data from the old old pay plan ($20 per 300MB data overage) so parts there could be questionable as to where it's from (the Mexico Bonus plan?).
From the FAQ:
Can I have both the Mexico Roaming Bonus feature and a new Mobile Share Value plan that includes roaming in Mexico?
No. The Mexico Roaming Bonus feature cannot be on the same line as the new Mobile Share Value 15GB or higher plan or the AT&T Roam Mexico feature. If you currently have Mexico Roaming Bonus on your device, this feature must be removed before you can move to a new Mobile Share Value plan 15GB or higher or add the AT&T Roam Mexico feature to your device. In most cases, it will be better to change to a new Mobile Share Value 15GB or higher plan that includes roaming in Mexico functionality or add the AT&T Roam Mexico feature, as you’ll have access to all of your plan data to use in Mexico. Mexico Roaming Bonus only provides 1GB per line before overage charges are incurred.
Here's the Mexico AND Canada version for the Unlimited plan... (May 20, 2016 plan)