Depends on what MS does. New security checks have been discovered but are not being used to their potential. This first appeared on FIFA 09. If this new security model was put in place, there's potential you'd have to update. And if a ban wave hits, they try and figure out what happened, fix it, and release new firmware.
Only once in almost 2 years has a required update come along. Wave 3 checks were begun by MS earlier this year and required changes. Supposedly, any additional Wave checks should be happened properly.