Vinyl sales may be growing at very high rate.

It is 100% growth rate when you go from 1 to 2.
Growth rate aside, there's an undeniable awareness of vinyl that slides into acceptance for many who were not really cognizant of vinyl five years ago. These same people also stream, if course, but they see vinyl as a fun, small complement to that streaming. 
Record Store Day is a joke and shouldn’t count, but sure makes up a portion of this “growth”. The majority of vinyl purchases are by people playing with a novelty. That article is trash.