I don't think Historia has been mind wiped. I'm pretty sure the royal family is so eager for Eren because they somehow lost the last person in their ranks who possessed the coordinate/mindwiping ability (probably the mystery woman). Basically, they' ve grown really weak and the SL is not yet aware of just how much.

If the royal family still had the mind wiping ability they probably would have used it by now. The thing those government dudes were holding out for was probably that Eren gets eaten by someone loyal to them and then they can beat Pixis and Erwin plus their followers with a mass mindwipe.