Yes, it is always a possibility that it might not get re-issued. If you would have just read some of these threads concerning this you would already know that getting an Employment pass is the result of two different but high important criteria.
1. Your qualifications and/or salary offered by the company.
2. Assuming you pass the first hurdle then the company MUST JUSTIFY to MOM WHY they need to hire a foreigner if there are Singaporeans or PRs who are capable of doing the job. This is usually the stumbling point even for those who already have EPs with their current company. The odds are in your favour but be advised that is does happen with some regularity, especially now that the economy is not it's best and contrary what the MP's might say in Parliament, what happens on the ground is another story. Course that's the same in every country.
SOME PEOPLE TRY TO TURN BACK THEIR ODOMETERS. NOT ME. I WANT PEOPLE TO KNOW WHY I LOOK THIS WAY. I'VE TRAVELED A LONG WAY, AND SOME OF THE ROADS WEREN'T PAVED. ~ Will Rogers