Well I am probably going to sound completly fangirl but please forgive me if I do. I think there are some good reasons as to why it wouldn't ruin the show if they brought him back a little LATER in the series (I said later because right now we are in the middle of all this Simon drama and it would be odd for it to happen now)
1: He would have the same personality guys.I mean he wouldn't be as well IK but he would be just as fun probably. He would also be a cool adventurer (maybe okay maybe)
2:Stealing princesses is really not showing much anymore. It used to be pretty much one of the main parts of AT but we have not seen much of it lately and it gets a little disturbing at times.
3: Because AT has other things to focus on. I really like the Simon drama but if you think about it AT has alot of other things to use. They have backstories romance (sorry I am not a big fan of that part but you know) maybe bring a few characters back.
4: because it could add more stuff to it. Maybe a searching for Betty adventure or reunion thing.
5: Because Simon deserves a life for being as awesome as he is.
I am open to all faults I may have. I probably shouldn't be writing this as i am to emotionally attached to this character but then again I am emotionally attached to them all.