The bit that puzzles me is...
Several series have already been published on the iPlayer as "box sets" - the pedant in me says that should be "boxed sets" but not for iPlayer because there's no box. I spotted this with some surprise recently when I went to the iPlayer to find some series my wife was watching. Sorry I can't remember what it was, it was that exciting. Although on TV they had got as far as episode 2, all of the series was on iPlayer. I then noticed several other unboxed/never likely to see a box "box sets" on there. This was back in November. So it's not "news" as such unless the news is that this is now policy, not just something that was happening.
Possibly it was the BBC trying out the idea.
They also seem to be using the on-line BBC 3 channel to try out series and then later transmit them on another channel. For example, "Class" is now being aired on BBC One.