By DLC OP probably means "patch", so don't get feisty people.
Sadly an interview before the leaks hinted they didn't want to do patches (at least for balancing issues) and or make money based DLCs, so adding new designs is most likely out of the question. Event Pokemon add ons for free however is not.
Only insecure and ignorant people try to debase someone online based on their username.
I would like to see Spotpass new 'mon, with some kind of check that finds out if the other system has the appropriate 'mon. Maybe have a placeholder model, just send the stats, and disable the nickname. That'd avoid any compatibility issues.