If that's the case, it's something easy to fix. If players currently own the SG Udyr skin, just set up a flag so that they get a mission of "play one game" and then are awarded the rewards after playing it. The infrastructure exists, it's what they use for pass missions. Rather than the flag being owning the pass, it'd be owning the skin
Discussed that...but the missions system is kinda unstable atm.