I'm not a money laundering expert but I thought the point was to get a bunch of cash, from drug sales or whatever you don't want anybody asking questions about, turned into legitimate-looking income. Income from Patreon might look legit, but how would you funnel your cash into Patreon contributions without putting it in a bank account first (and setting off the very alarms you're trying to avoid)?
Imagine I am in a shady business and want to collect $13000 a month clean on my bank account, without attracting IRS etc. attention. I can have people (or myself) load prepaid MasterCard plastic with dirty cash and subscribe them to my Patreon.
Not implying anyone is doing that, just that it looks possible.
You can distribute it across multiple subscribers. $1k/month cash deposits for 1000 people will raise less questions than $1M/month for one person. That said, whole operation looks rather expensive, there should be much cheaper and easier ways than fake Patreon accounts.