they won't throw the old stuff out, they'll use it until it's gone and then break open the new stuff.
When you're "re-branding" you don't want the old association still there lingering on. Regardless of how minor the changes to the new logo is I'm 99% sure it went through multiple draft and revisions, they probably brought in focus groups to test it and get it how they wanted it exactly. They won't just up and throw away all the beer cups and stuff and will probably donate them to a group home or someone else that can use them, but they won't be at the stadium next year. Its a new logo all around and the old one is gone that's how this stuff work.
Also does anybody remember what Uptown Charlotte looked like before Ericsson Stadium opened in 1996? Charlotte would not be the city that it is if it wasn't for the Panthers. The city didn't pay a dime for a stadium that brought so much to the community. I doubt the Big Cat will ask for assistance but if he does I'm sure it will be a sh*t storm because of all the crap that got pulled with the Bobcats arena. But the two in my mind can't be compared.