Well you never can say, it's football and anything can happen I mean there are teams that have done it before so it's very much possible that PSG can replicate their previous success although it's not going to be easy as most of the big teams are well aware of their pattern of play so they will likely more match their energy and make it very difficult for them to win. The Champions League is filled with lots of strong teams and most of them are now equipped with quality players ready to win the league.
Since the change of name to the UEFA Champions League, no other team has done it again apart from Real Madrid, before that, teams only tried but couldn't retain it until Real Madrid made it happen. The truth is, it will be hard for any team to replicate that form in the competition. PSG cannot retain the the trophy, yes I was a big fan of PSG last season and wanted them to win it and I was happy when they won it but they cannot win it again this time around.