There are no direct flights to the UK anymore. The view of the UK government seems to be that they laid on repatriation flights at the beginning of the emergency, a year ago and anybody who didn't get out at tnat time should now look to their own resources. Argentina is on the UK government "Red" list (The "Red" "Amber" and "Green" categories change like a set of demented traffic lights so nobody really knows if a country is considered "safe" from one moment to another) so they don't really want their citizens or legal residents coming back if they can help it. I imagine the attitude is similar amongst many/most other governments around the world.
If they don't want legal residents to return will they extend DNIs?