It is just a matter of preference. I still like the Dan generation a bit more, although I am really fond of classic Jon grumps. They both have their good and bad sides. With current Grumps, I sometimes feel that series go on for too long, when they should've ended way earlier. Trauma Center and currently Bloodborne would be two series for me. With Jon, they often ended series too soon. Yoshi's Island and Resident Evil were funny and also very interesting to listen. I sometimes miss that they don't talk about games as much, but I really don't miss that Jon & Arin sometimes just fought and argued for the sake of fighting and arguing, especially when they don't have a clue what they were talking about (A Link to the Past). Both have their positive and negative sides, it's just different for every person what those are.
I personally don't feel that Arin is burned out. I got that vibe late 2014/early 2015 but right now, I think he is enjoying it once again. It's not like this didn't happen in the Jon era. The last few months weren't as awesome as it was before, at least for me. It just depends on their mood and you can't always have a great day.
When it comes to Jon's departure, I think I have a pretty good theory why they never talked about it. I recently started watching the Completionist, because he (Jirard) is currently guest on Grumpcade. Great show btw, I highly recommend it. For many years, he did the show with his friend Greg. A few months ago, Jirard posted a video that Greg is no longer part of the show and that he will be missed. You could call it an "Ode to Greg" The fans started going apeshit, very similar to back with Arin and Jon. The difference is, that Greg started posting stuff on Twitter, saying that they aren't friends anymore and gave more insight. You can read everything about it here, if you want to. Now that we got the backstory out of the way, here is the really interesting part. Another Youtuber and part of Polaris, Strippin, responded to Greg's tweets. Just click here. NDA stands for Non-Disclosure Agreement and Greg broke it by tweeting about it. My guess is, that Jon & Arin did the same thing. Game Grumps is also part of Polaris (and I think JonTron is too) and I wouldn't be surprised, if they were pressured to do so. It's just a theory but I think that is the reason why neither of them really gave us a real explanation on what happened.
