IIRC, Vargas minor league history also indicates he is far better as a LH hitter. I heard someone from the Twins organization say that last year was a surprise because of the reverse of his splits. He looks much better LH this year for sure.
I looked at the numbers going back to 2013. Don't know if his numbers from A ball or lower have much relevance. Kind of a mixed bag. It looks like he definitely hits for more power left handed. But in some seasons he hit for a higher average right handed. That actually is the case at the MLB level. His ISO as a RHB is .150 ish and it is over .200 as a LHB.
Disclaimer: BR lumps minor and major league splits together in their minor league splits page.