You can it would not complain about license, sepm 12.1 SMB will not download defs if there is no license, sep enterprise will download but would show warning
There are two SEP products i.e Small Business Edition & Enterprise Edition
Types of enforcement
When the license goes out of compliance the Symantec Endpoint Protection product goes into enforcement mode. There are two types of enforcement
1) Hard Enforcement: SEP 12.1 Small Business Edition
- Content update downloads stop for both server and clients.In Small Business Edition it's 1:1 mapping with CAT server.
- UI changes and log notifications are started.
2) Soft Enforcement: SEP 12.1 Enterprise Edition
- Content update downloads continue from all the sources.
- UI changes and log notifications are started.
In your case it must be Enterprise Edition, Clients and servers are still protected even though number is exceeded..
In Enterprise Edition there would be not be any impact on the product functioning.