Answer: If your installed Beta or Evaluation copy of Foxhound expires, you will be still able to view the History portion of the Monitor Database feature, as well as view your Foxhound Options and Alerts Criteria settings. However, the Monitor Database process will not gather any new samples and by implication the Alert process will cease to function. Also, the Display Schema feature will be disabled.

Other limitations may be applied to the installation of new builds; e.g., the end of the "Free Upgrade" period. These limitations are not yet fully defined, but they will take the form of requiring you to provide a new registration key to activate the new build. This is not the same as expiration which prevents full use of your old build: if you don't have a new registration key for the new build, you can always go back to your old build.

See also...
What is the upgrade policy for installing new builds of Foxhound?
What is the Foxhound End-User License Agreement (EULA)?
What are the differences among the different editions of Foxhound: Beta, Evaluation, Basic and Extended?