Most modern PM's are actually much more resistant to RF induction than one from strong magnetic fields mainly due to the saturation of the RF spectrum over the past 2 or so decades coupled with a decline in high voltage power in populated areas (they are underground as well as farther from residential areas these days).

That said I have no idea if the field those things generate is strong enough to create any issue with PM's or similar devices (like the "jump start" internal defibrillator some people are getting these days).

I would think that these devices are quite safe, especially considering that you see wireless charging station in courtesy area's in lobbies and other public places without any warning signs.