Once you stop for a season it's very hard to come back again. Also cast members will move on, they aren't going to sit on the side for a year and then all come back. People need to work to live.
My guess is one of the major cast members decided to do something else, and the whole series got derailed, fitting since the last season was about a train. "Taking a break" LMAO that's great PR work by showcase, but probably not the entire story. It's over, get over it and let's see some talent come up and take it's place. Doesn't even have to be in a trailer park, could be some other setting but with the same humour style.