Neon takes awhile to replace, especially custom stuff. I'm thinking Disney didn't have backup replacements made so the things now on back-order or something. It is odd to see it go out so quickly though.
Random tidbit: The "Gone with the Chin" neon sign in the main boulevard of Hollywood had been broken for a long period of time during 2011 (as in, physically broken), and was eventually replaced sometime in early 2012. Something tells me that they're aware of it, and it has to be custom made for it. That's what it seemed with the "Gone with the Chin" sign, at least.
Re: Maters Jamboree's condition, its my sons favorite ride so I always talk to CM's there. What happened was right after an epoxy was put on right after Cars Land opening, there was an unforseen rain storm that ruined most of the epoxy. CM's on that ride tell me it'll be repaired in the "off season".