First, is this a limit of post, like 1K? Also, isn't GogoRiki one of the two E/I shows 4kids is forced to show due to the CW4kids block agreement with CW? I would think 4kids would want to get E/I programs out of the way early. Sonic X isn't doing good IMO because kids are noticing they aren't new, and this is also my opinion on why the CN airings of 5Ds haven't been so high. If 4kids let CN air the previous weeks episode, then kids could watch CN at 8:30, then watch the new episode on CW, which could even be advertised (doubt CN would do that) at 9. Just my opinion though.
While I definitely wouldn't mind it if Cartoon Network started to show the previous 5D's episode, especially if new episodes will eventually air only there, I don't think that it's 4Kids who isn't letting them do that. I don't really think that they could tell another network when to air one of their dubbed show on their lineup. Cartoon Network decided to keep new to the channel episodes of 5D's on Saturday morning so that it didn't catch up to the CW4Kids airings. It also could be that Cartoon Network only has the rights to air the first season, similar to how they have the rights to air only the second season of Chaotic, but I'm not sure about that.
Even though Cartoon Network still hasn't promoted 5D's on their lineup, they have given it decent treatment with a few rerun slots during the week and a few marathons when it first came on. It's ratings aren't that great, but I thought that it was doing fairly decent on their Saturday morning block.