User blog comment:Omega natsu2/Mega's Vacation/@comment-4829046-20130721171012/@comment-5840892-20130721174231

I don't know...I doubt it if you form a strong enough bond with them. According to the plot of HG/SS before Pokeballs, trainers used to walk with their Pokemon...So maybe not. But I some did go rouge/wild again after the ball was destroyed with them out of it in Adventures.