IIt means that, after this batch, the event stops till we decide to run it again (I wouldn't expect it sooner than in a few months). Releasing too many flames at once would bring their value down and frankly, flames are already pretty cheap and affordable. The only batch with a theme to it was the second one (pairs), different ones might happen in the future.
As for the requests, as I've once said, it's possible but it'll be implemented when and if we decide to implement it (and when/if itemdump builds up its stock of flames to the point that would give some room to choose different flames), so I can't give you any specific information, it might not happen at all.