I don't think Steven is wearing armor, but that he's been dressed up by White Diamond since she's convinced he's still Pink Diamond.
If the new episodes are weekly, does that mean only Legs From Here to Homeworld is airing on Dec. 17 since it hasn't aired on TV yet? Then again, the way that episode ends seems like it was specifically built to be part one of a two-parter.
I'm hella interested in Connie's new sword.
EDIT: According to this press release (
https://www.broadcastingcable.com/news/steven-universe-back-on-cartoon-network-december-17), this is a 5-part arc that will conclude in a "finale special" on January 21. Calling it a special may hint that it will be a double-length episode like Reunited. Also, this arc will have FIVE songs (one of which has to be Escapism at this point).
The press release also mentions that the show is returning with a "new season," so I guess CN really did treat Reunited as a season finale.