Server able to edit the PlayerGui with FE on and no RemoteEvents?

Yesterday I was tinkering with some GUIs and I stumbled when I ran this script:

for i,p in pairs(game.Players:GetPlayers()) do
    p.PlayerGui.ScreenGui.TextLabel.Text = "Hello"
end

When I put those 3 lines in a function that was fired via a ClickDetector's MouseClick event like so...

script.Parent.ClickDetector.MouseClick:Connect(function()
    for _,p in pairs(game.Players:GetPlayers()) do
        p.PlayerGui.ScreenGui.TextLabel.Text = "Hello"
    end
end)

...and then ran the script, believe it or not, the server script accessed the PlayerGui and edited the TextLabel with FE on and no RemoteEvents. Could this possibly be a bug?