Short version. No.
Longer version. I could see a theoretical option where something fun was done with things (either sending bad data in a link play mode to effect some kind of takeover*, maybe a more conventional multiboot option or just by being a cheat device and sending say hacked pokemon back in a game like that**).
Assuming simple link options for pokemon and it its clones is not your thing then find something to dump the save (many options but if you have a DS or DS lite and a DS flash cart then many choices there), cheat on that however you will and send it back.
*I don't know if you have ever seen the things where people do a bunch of actions in a game, trigger a glitch and then said actions sorted the memory in such a way that it plays a little demo. Same idea except here you have easy arbitrary data options and even calculations so better still. Theoretically you might also be able to do such a thing with a save hack.
**part of the reason GBA link play over network is hard is because both consoles tend to maintain their own game and communicate rather than one master host and a bunch of slaves like many modern games so not like you can host on a device you control a la some modern cheat efforts and workarounds.
The DS has Nitrohax which works by setting something up on a flash cart, ejecting the flash cart and then booting into the game. The DS however is far more tolerant of cart ejections while it is powered and works in a manner slightly more amenable to such things than the GBA (the DS copies code to memory and executes that, it is not impossible to do that on a GBA, indeed multiboot and fast code might be considered just that, but it is far more limited). There is a GBA cart swapping save dumper but most consider it proof of concept and usually quite tricky (most SPs tend to reset if you try it and I imagine all those nice altered screen originals are going to be similar).
