This headline is overstating it. Yes, there have been two cases in the past few months, but this is two cases out of tens (hundreds?) of thousands of booked rooms.
That said I'll probably check for this next time I stay in an AirBnb.
Not only that but hidden cameras have been a thing in cheap hotels 'round a few countries for some time (perh since the infamous "X10"). So it's not all that new a phenomenon and definitely not relegated to AB&B --though they get the most press about it, of late.
Well the shown example suggests there might be better hidden ones not found.