I won't speak on Decade or Shinkenger because I've only seen the first three episodes of Decade and haven't seen any of Shinkenger, but on the subject of RPM and Dragon Knight, I'm glad people are enjoying them, but I feel people are jumping the gun on them.
People are talking about RPM being the best season ever when all of THREE episodes have aired. I've enjoyed the hell out of those three episodes just as much as everyone else, but come on, it's WAY too early to be praising how awesome this season is. We could've said SPD was the best season ever after three episodes (and knowing this board, I bet a lot of people DID), and we know how THAT season went. Jungle Fury's first three episodes were pretty good, too, but episode four and beyond were terrible.
I just feel like people in this fandom have become WAY too beaten down and disenfranchised because the last few PR seasons haven't been that great, so any time they see anything that's even halfway decent, they jump on it and start praising its name.
It's exactly why people on this board were jumping to come up with excuses for Dragon Knight even though its first few episodes weren't that good.
And look at how people on this board were jumping up and down praising SPD and Jungle Fury were the greatest things ever, now those same people are shitting on those seasons (and those people know who they are).
So, I guess my point is, I don't know if it's REALLY a revival (at least on the US side), so much as people are just DESPERATE for it to be.