Events like Lunar New Year but for single player/campaign

It just came up to my mind that it would be cool if events like that would also be available for single player/campaign like beat a level on hard difficulty (or moderate), finish a campaign, beat a level under 30 minutes or something like that. The prizes could even be new icons or some skins for single player for units. Think about that! There are people that play single player content only. Cheers!