no you miss understand. You can clear and keep chain, as long as you pick up a block (any block within 1 second of the match and keep picking up blocks until you have another flashing match). (you dont need a match to keep chain as long as your picking up blocks.) But rember its more important to keep chain than to get the clear bonus. But to get a really high score you need to be clearing nearly every match and keeping chain.
Old message, but huge, huge pro-tips here. Even though I'd been chaining on many songs for a long time, the fact that you can keep the chain going for about a half-second to a second AFTER the match clears just by hitting/dropping another block is really frankly unintuitive, and important.
I wish I'd read this earlier - it was a revelation to me realizing recently that you can hit the Pusher 100% clear bonus while keeping the chain going! The timing seems harder than usual since you have less time to pick up a new block, waiting after the match clears, though tell me if I'm missing something.
In general I think chaining (at least in Elite modes) should be more obvious to the player, but I get how adding more things on-screen to the GUI and such (think of a combo/chain meter, EBA/Guitar Hero-style with numbers and notifications vs. the current chain bar) might add more distraction visually and take away from the sleek look of the game, but the depth of these modes is not at all clear and barely hinted at in the game itself.
Audiosurf