The only limited time rewards are the Reman BO, and the badge rewards for completion. Other than that, everything stays
Because of this, I haven't had much motivation to replay them all, as I made sure to get the Reman boff on every character I have when the series was new. Still, great episodes for sure...
Thats good to know because like you, I've got the Reman BO on all my chars already. I had thought the new Horta schematic was limited time, good to know I can in fact take my time on them though.
Having said that, I'll probably be on tonight for a run through as I fancy getting some of the accolades while the episodes are popular. That is unless I get sidetracked into an evening of PvP again - logged on last night to run The Vault, logged off at 2:30am having done nothing other than PvPs but it was fun