Their good performance gave them lots of rivals last season and some would be coming back for revenge this season so they need to be prepared for the challenge ahead it's not going to be easy cause Chelsea has exposed their weakness in the Club World Cup but I trust PSG to tackle that error, I'm suprise they didn't make much signings though.
I think Paris Saint-Germain currently has a very good squad, and making too many transfers doesn't make sense. They have a squad that won the Champions League, and they want to maintain this core core. Manager Enrique probably had a similar report. Paris Saint-Germain, with no need for transfers, is a team that can extract huge bonuses even from players on loan. It's as if they've built a squad as good as a football manager. Even the players they sent out on loan are considered stars. Perhaps that's why the manager hasn't allowed any new players to be transferred.
Recruiting players isn't wrong because we don't know what will happen next season. I believe PSG has good players, but if one of them gets injured, it will affect PSG's future performance. Therefore, recruiting players is something that should be done to complement PSG's roster and avoid the risk of fatigue, as Luis Enrique can rotate more freely.
I'm sure after participating in the Club World Cup, the players will still feel tired and may need more rest. Luis Enrique could develop new players if PSG makes a transfer. Unfortunately, I don't see PSG signing any players yet.