Living in Argentina myself, I figured I would leave my two cents on this one.
The issue with his retirement goes beyond his ability to perform.
There is a known problem with him and the national soccer association (AFA in spanish) regarding delayed and improper payments and lack of organization. The whole thing started at least in 2014 with the Wolrd Cup, and has been dragging all along.
Already by Thurdsay, the rumor existed that all this would happen, particularly the retirements, and this will probably affect Martino as well.
As long as the AFA doesn't get its shit together, there is a good chance the guys will not be back. FYI, it is an organization that has been ruled by virtually the same regime since the last dictatorship in 76, and its level of mismanagement, corruption and general disregard for both the people and the players may have reached its peak. By about friday, FIFA had decided to intervene and remove the current leadership, but the local government may refuse that, so who knows.
Back to Messi (I just wanted to provide some context), I can only imagine how frustrating this may be, and as it was pointed out previously, he has always had this issue when playing finals with the team.
Time will tell I reckon.
At any rate, I had the pleasure of experiencing the world championships in 78 (albeit very young) and 86, and it is evidently doubtful I will see one more in my lifetime