That is not what end of support means. End of support means just what is says: Microsoft no longer offers support on it. Meaning: if a problem you have is caused by using XP, it'll remain unsolved. Unless you can also reproduce it using Windows Vista, 7 or 8.
Security updates often are made even well after the end of support (at least for fi. Windows 2000). In particular if an issue is found that is also present in later versions, the earlier versions will often also get patched. And as I stated: XP embedded is still not in it's end of support. For that reason alone, XP will receive security updates at least till 2016, no matter what Microsoft says about it's "normal" OSes. Plus there's of course the XP mode in Windows 7, which is nothing more than a recompiled XP source with a few minor changes so it plays nice with Windows 7 as a host OS. They can't stop support for that, as it's officially part of Windows 7.
But heck, if it's corporate policy to remove everything called XP then you shouldn't object, but point out they should at least give you the budget to purchase a few nice and shiny new DMM's that don't rely on XP to get any work done.