Hello Fabio,
Please have a look at this link below:
https://supportforums.cisco.com/discussion/10512071/what-happened-if-client-doesnt-renew-license
This link has all the information of you want know about the behavior of your device, if the Reputation, AV and Anti-Spam services cease their function when the license expires.
I hope this solve your doubts.
Fabiano de Freitas
CSE
Cisco Security Customer Support