This seems to be the statute: https://www.leg.state.fl.us/Statutes/index.cfm?App_mode=Disp...
With the obvious IANAL, it doesn't seem to rely on the message be sent to the person being threatened. The specific segment is "in any manner in which it may be viewed by another person".
This may be one of those cases where we get to find out how courts view SaaS platforms.