"Law 12:
Indirect Free Kick
An indirect free kick is awarded if a player:
- impedes the progress of an opponent without any contact being made"
It should be a foul.
If Vicario were to "BE STRONGER" like pundits seem to suggest, give the attacker a little shove when the corner is delivered - you can bet a penalty would be given against us and not many other teams.
It's kind of a situation where the referee can just allow what they want. Historically keepers were protected and couldn't be touched in the area. Now it can literally be whatever the ref does or doesn't fancy or find funny.