Hah. Regardless if Jack Dorsey was a bitcoin bull since forever, I personally agree and think this was also a publicity stunt by Dorsey. Since the MicroStrategy bitcoin acquisition, people on Twitter(Pierre Rochard, etc, If my memory serves me right) were pressuring Dorsey to "have more skin in the game" and actually allocate some of Square's money into bitcoin. Hence, it's safe to assume that he allocated a small amount just to gain better publicity even though it literally doesn't make sense for a growth company to be investing in "hedge" assets.
Though I guess the 50m gave them a lot of press coverage so it probably ended up being worth it? Idk. 🤷♂️