They do? Where does that piece of info come from? It's not part of WCAG 1.0 or 2.0 as far as I'm aware. In fact I'd argue that it's risky to depend on the title attribute being rendered at all. Most experienced screen reader users use a non-verbose setting in their software to stop the title attribute from being rendered as, 9 times out of 10, it's more "noise" than "signal".
Switch, VR and sighted keyboard users don't have access to the title attribute at all, which means your link titles wouldn't be Perceivable to these user groups - a primary WCAG 2.0 failure if you were relying on the title attribute in any way.
So, personally, I'd take that info with a very big pinch of salt.
If you want to use a real-life yardstick for AAA compliance, check out http://lflegal.com/ It's one of only 2 officially recognised WCAG 2.0 AAA sites. And it uses WordPress.
Personally, I don't push for AAA - if only becaue of all of the documentation that must also be made available on the site. I'm quite happy with strong AA.