I believe him also have thought it through and I believed his presence in this coming World Cup would rather be a motivation for the young once, they would need him to be their with them, to inspire them and share his experience on how tournaments like this are played.
Winning the last World Cup the whole world though Messi would retire on international games but since then he have always prove why he needs to be on the pitch, he bring in a lot of quality in that Argentina team and I still think it will be needed in the coming World Cup.
But I believe this would be his last dance in a World Cup tournament, he is a living legend and he has won it all internationally so let hope he enjoy his last dance.
If you look at him even at this is age he is still very much important to the Argentina national team, we all thought they would have it as their last dance just like we saw Angel Dimaria did but Messi might be looking at cementing his legacy more, winning a second World Cup will simply place far ahead of his rivals on the greatest of all time log. For me I think he certainly will be retiring after this World Cup and sincerely with him in the squad this Argentina team look very much the favorite to win it.
I personally though do not want them to win it because this time around I am rooting for Portugal because of Ronaldo and also this golden generation. This current star studded Portugal team need to win something huge so they are not like the Belgium golden generation that didn’t win anything