My mistake.
After reading their reddit comment, it still sounds like an upstream issue.
There are technical limitations to being able to implement permanent/advanced Kill switch on Mac, however, that is not to say that our team isn’t looking into the possibility of making this a reality at some point.
If technical limitations are truly the reason for the issue I do not think that is a good basis for removal.
As for the Linux issue, my opinion remains unchanged from the original comment.
I do agree with @Anvil that Proton does not technically meet the criteria but I still do not see the issue meeting the bar for removal. Thats just my opinion.
I do think the criteria could be changed to be more broad as I don’t see why the client itself needs to provide the kill switch if the functionality can be obtained in a different method (ie such as using the wireguard client instead of protons).
The again I am of the belief that VPN connection should be done on the router level and not on a specific device, which avoids this issue altogether.