When you combine it with his somewhat brief period in 2015 it is even clearer. 2016 was a throw away year for him, he hurt his wrist and when he came back it was pretty clear that his bat speed and control were not the same. It is good he tried, it shows something, but really you have to just throw those stats away to evaluate him.
By that logic he has been solid for his entire time in the majors so far. He is an athletic OF who makes plays and a dangerous hitter with good plate discipline and some power. He is at least a good starting OF. Sadly, he doesnt have many solid players to play with at the moment.
I still think you are overly optimistic about Galvis. He has some power now, but his approach is still questionable, he still avoids walks like they are going to hurt him somehow and his approach at the plate is still not very good in my opinion. He swings at alot of bad pitches, but he isnt as bad as some of his teammates. His power is surprising, his 1st HR yesterday went into RCF in the middle deck, if someone had seen that 2 years ago he would have been tested for steroids on the spot. He has learned (or been taught) to have some upper cut in his swing (not Stairs, as it started last year) and he does pick out pitches and try and drive them, which he did not do when he was younger. He is noticeable bigger than he was a couple years ago, he has clearly added lean muscle to his frame, not a ton, but it appears to be "good" lean muscle and has improved his bat speed. It is improvement, but he is still a below average hitter because his OBP is so bad, but the power makes him at least an acceptable #8 guy. His defense has always been good and I think is actually underrated from watching him, if he was a better hitter he would be a Gold Glove SS (yes, I said that and meant it).