Yes I would. As long as it could fit in nicely with the other stuff I leave guests (maps, tourist info leaflets etc). If it was a similar look and style, not too spammy looking, just a simple flyer... I'd be ok with that.
I personally think its a good idea but I know there will be others who disagree.
Not sure how to contact all the hosts though, other than messaging them through Airbnb which is I think against the terms of service