do employers get notified if an employee apply for new visa
no, his current employer will not be notified if you petition for a H-1b on his behalf.  however, if you do apply for a change of status and that petition is accepted in the lottery, if he travels the change of status portion will be terminated and even if the h-1b is approved, he would have to go abroad for consular processing.  please let me know if you have any additional questions or how i can be of further assistance to you in this matter.