It is mostly meaningless because it's likely a marginal upgrade on the most expensive card in the deck. No well formed plan for a Workshop matchup revolves around beating specifically Triskelion because Triskelion is not what you are losing to.
As an anecdotal illustration, the last time I was in a position to lose to specifically Triskelion, I had to find a preventative answer. I had the distinct displeasure of having Vendilion Clique in my deck, but Clique was good enough to prevent a topdecked Triskelion from beating me on the spot. When Vendilion Clique is an answer, the question can't be that relevant.
My point is that it doesn't matter what expensive card Shops is relying on to win the game in that spot as long as Shops is playing the best possible card. While I'm far from convinced that Skysovereign is that best possible card, I'm pretty sure I don't really care. Then again, I'm the one playing 4 Lightning Bolts and zero Plows in a format full of 4/4 and 5/5 Eldrazi. And loving it...
edit: to phrase it a different way, if your plan for Workshops depends on the difference between Skysovereign, Consul Flagship, and Triskelion, you didn't have a good plan to begin with.
This assumes, as your previous post, that the debate is whether to run Trike or Sky Sovereign. We could see Shop decks emerge that use both, while maxing out on one. For example, I wouldn't be surprised to see a 4 Trike/1 Consul deck place in a Top 8 in the near future. The fact that Shop decks already in many cases run 4 Trikes suggests the possibility they'd run 5, or more, if they could. Trike is one of the best cards you can play against Gush tokens.
That could make a significant difference to the analysis as you've laid it out, let alone your opportunity cost observation. We've seen many games in 2016 Vintage where the critical turn in the Gush v. Workshop matchup is when the Gush pilot barely sneaks a token generator onto the table, and the Workshop player either has the Trike or they don't. If they don't, the Gush pilots wins. If they do, the Shop player wins.
Most Gush strategies don't have preventative answers, like Clique, to Trike, aside from Force. Some run Cabal Therapy, but not most. Instead, they rely on good timing, superior consistency, and after the fact removal. Upping the Trike count could conceivably tip the balance even further in favor of Shop pilots.