Short answer not yet. I think the best thing to do at this point is provide awareness and education on the privacy settings that those assistants have. For example, in Alexa you can disable the feature that allows Amazon employees to review recordings, have an audible alert and light from the Echo device after the wake word, physical button to turn off the mic, and delete recordings on set time frequencies or manually.
It can be put in a policy but it's not really enforceable if the Staff are at home. Maybe a reminder technique before official business is discussed is to remind everyone to turn off or disable all smart assistants in the immediate vicinity. It doesn't help with one-on-one customer calls of course but it could help establish good privacy habits.
For max privacy, I'd recommend turning your cell phone completely off (Not a new idea of course). I've had products advertised in my Facebook feed that I've never searched or typed in a text message but we were discussing it during a meeting or conversation. "Tin Foil Hat Engaged!"
