I am a GP, not cardiologist or AME.
If you do turn out to have WPW, the electrophysiologist will probably try to stimulate an arrhythmia. Depending on whether he can and how easy it is, will, I suspect, depend your chances of a Class 1 and any restrictions to be attached to it. The fact that you have never had any symptoms is strongly in your favour.
If you do have an easily stimulatable arrhythmia, which seems a bit unlikely, then radio-ablation of the abnormal conduction pathway may completely cure you.
Don't give up heart at this stage by any means! You may not even have WPW.