This topic has been discussed before, and the article doesn't put forth any new evidence. Surely, $1200 purchases are very suspicious and might lead to thinking people put their financial support money into Bitcoin. Maybe some of them actually do, but I don't think the available evidence is conclusive. For example, people could learn about the $1200 being the sum of money people in the US receive and symbolically put the same amount into Bitcoin to attract attention or to express what they would've done with the money. Or it can be a totally different thing that I cannot come up with.