I’m afraid that at this moment Google Wallet notifies the user only that the subscription has been canceled.
I also asked myself on the google wallet for the forum of digital goods:
https://groups.google.com/forum/?fromgroups=#!topic/in-app-payments/YFaCBDwaF9g
See the second answer from Mihai Ionescu from Google
EDIT: As suggested in Qix below, I quote Google's answer below:
, - 2012 , 2014 , , , Google -