I don't work for Eagle, but have spent some time in hiring departments. Do not under any circumstances tell them. While it's illegal to not hire you based on a future medical issue, we all know there are plenty of reasons they can find to not hire you. Legally they are prohibited from asking you ANYthing about your health, so the only way they can find out is if you volunteer the information. Hint: don't volunteer the information. People get sick or injured all the time; it's something companies plan for (i.e. reserve pilots and junior assignments).

Also, they can't terminate you for going on medical leave within your probationary year either. It is true that during your requal training (if required) they could conceivably terminate you for performance issues or the good old "good moral character" during the check ride. This, however, would raise a plethora of legal flags that any two bit freshly barred lawyer could use against the company in a wrongful termination suit. It would be an open and shut case for you, with the company probably settling. The legal system looks extremely unfavorably on anything that could be construed as retaliatory termination after medical leave.

Basically, nobody should ever be afraid to go on medical leave if you have to. Just make sure it's documented.