According to official UEFA Super Cup regulations for the period 2015-18 (link here) article 9.04, 40 gold medals are awarded to the winning team. And it's not mentioned that only players who are in the match squad should receive a gold medal. Thus Cristiano Ronaldo could receive a gold medal.
It's hard to believe Cristiano Ronaldo could receive a medal when he wasn't even part of the substitutes. In most competitions you have to be at least part of the subtitutes, and in some competitions if you were always a substitute and you were never in the field, you don't receive a medal.
Cristiano Ronaldo's official page is not listing the UEFA Super Cup 2016 in his palmares.
In the player list of the UEFA Super Cup 2016 in UEFA's official website, he isn't listed either.
So, he wasn't part of the startup team, he wasn't part of the substitutes, and he wasn't part of the whole list of players for the cup, there is no reason to believe he got one, because he couldn't even count as part of the "wining team" even when some fan websites are listing the cup among his trophies.
If you check the official Real Madrid website, you would see he has 2 European Super Cup medals in his awards.
So, Ronaldo definitely received a gold medal.