I think anything's possible and the "online only" thing is a rumor started by another site, nothing to substantiate it (yet). I could see it happening though... the line's on life support and if retailers aren't ordering in quantity, this turn of events could be a clear indicator that they would only do these as an exclusive.
The EU wave was solid new, had a highly desirable movie-based BAD figure, and had insanely hot figures in it... and it became exclusive. So the precedent is there, for certain.
I'd forgotten the Royal Guard... I'd want more of him, but I could also see some of these getting re-releases down the road, whether the wave is made exclusive or not. Plus I was pretty ok with the ROTS figure despite people's complaints. I'd take a hefty dozen or so more of those figures in my collection. They were pretty sweet though pikeless. I have pikes from the new TPM one though, so I'm good. I'll make new softgoods if the need strikes.
I dunno what to say on this though other than C6 is right around the corner and I think answers will come then.