3rd party resellers or indirect agents such as Walmart will not honor your employee discount for phones or accessories. However, if you're eligible for an upgrade then you don't need your employee disocunt to buy phones from them. You can just upgrade and you'll keep your existing phone numbers, plan details etc.
Thanks for your reply. Does that mean that I can buy my verizon phones on walmart.com as an upgrade (verizon told me all of my phones are eligible as my contract is up in less than 2 months) and my current contract with my gm employee discount will be extended 2 years?
That is correct. Just make sure you read the fine print when it comes to dealing with an indirect agent. They have their own policies for returning/exchanging the equipment that may/may not be different than VZW's own policies.