I don't doubt the post from Matt is real. If it weren't he likely would've been quick to deny it and it also sounds like him. He's a big fan of the show and he's probably going a little farther than he should, but he has been much of this season. I kind of admire that he's standing up for what he believes and wants even if it risks some tension with his employer. It's always nice to see people who aren't just "yes men". What he says is certainly true. Contrary to popular belief petitions, letter writing, complaining, etc. do work, the catch is it's the numbers that matter. If a few million people sign that petition we'll all be watching Bill and Ted next year. Now if it doesn't even cross 10k-100k it's fairly insignificant. I believe there is some truth also to the outrage being less than expected. Universal handled this in the best way possible. Had they just outright cancelled the show with no warning I would've been one of the first to cup up my AP and never set foot in the resort again, however they handled it in a way that softened the blow and gave us a chance to appreciate it one last time. While there's a handful of us who will make changes because of this decision most people will still attend and still spend money and at the end of the day the impact will not be overly huge. In the theme park world it seems unfortunately new is always better than good (see: Fast & Furious) and everyone will still line up to see all the new offering and soon forget all about this.
As for the show being cancelled it's really been a long time coming. The show has essentially been in trouble for almost 10 years. From the legal issues with Disney characters up to the 2012 show complaints there's always been good reason why Universal just wouldn't want to deal with it. I remember in 2013 there was very real concern the show would be cancelled during the run that year or not return. Everyone seems to have a theory, my personal theory is with the contract being up someone probably started the process of looking into renewing. This would obviously require approvals and at some point some upper executives got involved and decided it was time for it to go. Mike Aiello and Jason Horne have both made it pretty clear the decision came from the top and was last minute. This isn't something that anyone involved with HHN wanted to happen. I'm sure they're all secretly hoping that theres a huge fan backlash and the executives will have to cave, but realistically it probably won't happen.