The executive was mandated to produce a list of individuals that can be consumed in oan actionable way by industry, such that it can prevent access to the U.S. financial system.
It did exactly that.
These companies got that list, their legal, risk, and compliance departments got in a huddle, and they laid out an action plan to try to get ahead of the regulatory action, while minimizing any risk of contamination or liability.
The government did not tell them to do that. Note, this is by design. The government telling them to would be unconstitutional. Rather, they acted in their own way, which to them rang as reasonable.
That is how it rolls. Is it fair? No. Is it right? Arguably not. Is it concerning? Hell yes.
Lots of things that some find distasteful are accepted though. Recently, along a similar vein, the whole "they're private companies, they can censor who they like" crowd made that clear. Hopefully none of them will be surprised or upset by this action.
As far as I can tell, the executive branch was not mandated to delete anyone who contribted to/was a "member" of the github tornado dev group.