When you consider how people speak, it's just one step away from being able to mimic basic conversation which to an extent has devolved to "how was X show" or "did you here about y".

So pretty much Alexa who most likely overhearing what you are saying and your opinions will be able to not only the mimic the voice of the deceased but also mimic their opinions of shows based on their previous opinions of other shows and what they've watched and if they've ranked said show high.