We'll probably make a change to improve this at some point, maybe allow users to re-submit the same image again if it gets disapproved from a particular stream due to "wrong stream".
Automatically switching memes into other streams would open a big can of worms though, since it would encourage users to just choose the wrong stream every time and let the mods choose everything for them, making a lot more work for the mods. It would also allow users to effectively gain more submissions per day for a given stream, because they could just submit e.g. 10 political memes across 5 different streams and count on the mods to move them all into a politics stream. There are also often multiple streams to which an image would be a valid submission, and users may not want mods to make the decision for them about where it should go.