I think this is a bug but I'm not sure. I was playing regular ARAM and I had the poros from Poro King mode following me. I had a poro summoner icon equipped so I figure that's what is causing it but it seems like a bug that they even appear outside the game mode.
no
Poros are ALWAYS in ARAM, just like snowballs are allowed. The only difference is in poro king, snowballs are mandatory, and strikes add up to summon the king. In ARAM, the poros are just for local color and background. However you can feed them a biscuit to see them dance around.
Can we call it a feature and leave it in?
From what I see, the price is 250 RP. I doubt Riot is stingy enough to make you pay that for a feature you can only use a couple weeks a year. I don't know many people who buy poro skins. If it's working and you felt you got your money's worth, I don't see the end game here. If you paid for it and it shows up, are you unhappy it's working? My guess is the skin is for poros regardless of mode. I haven't seen anything specifying it was to be during king only. Much like ward skins don't work in aram since there are no wards, your poro skin only works in aram or the poro king mode. Seems fine to me.
