This makes sense.
Gronkowski suffered from multiple, and some of them very serious, injuries during his career and one of the primary selling points for CBD is that it helps to relieve pain.
However, I think the more interesting thing about this is that Gronkowski waited until after he had retired to become a spokesman for a CBD company. Even though CBD is in a seemingly ever-changing grey area legally, it’s a product that seems to have wide ranging support from many parts of the economy.
For Gronkowski, and I would suspect most other professional athletes in a major sport, I have to think that becoming a spokesperson for a CBD brand is frowned upon, if not against contract (there are some current professional athletes who are open about their CBD use but most are retired). Even if CBD were completely legal I think it will take some time for there to be a popular professional athlete who will be a spokesperson for a CBD brand.