People will still be able to dethreat it will just be a tiny bit harder to notice when you've achived it or not.
Defently not, When you get a teammate that plays poorly you will still be able to notice a threat difference and poor matchmaking
If anything the problem is the fact that matchmaking never had the proper ability to give fairmatches not the fact that there is a visible threat system you're pointing it out yourself.
Visible threat wont make a difference, you will still notice when matchmaking gives you a unbalanced match which seemlingly is your main argument