First, it's not in black and white anywhere. You're a RCA. You're a sub. You're bottom of the barrel. Everything a regular does wrong, and you yourself also, will be blamed on you!! Accept your fate.
However, it's Xmas time, everything goes out the window. You're going to be sent on routes you've never done; you're going to be called in at 9 in the morning to case and deliver a route you've never done, and BTW you better be back by 5; you're going to be called in to do 'parcel runs' at 5 a.m. on your day off after doing 4 13-hour days in a row.
Black and white doesn't apply to RCAs; we're just an afterthought.
However (big however) since you've been on this site since April of this year, which means you've worked for the po since then, and you're still not getting called in to run other routes, I would start thinking of another job prospect; they're just keeping you on til after the holidays. Nine months is a long time 'learn a primary'.
Here's hoping you have your 90 days in.
Good luck.