Replacing him will open a big question tactically.
Because Raphinha is more of an off the ball winger. So will they replace him with someone similar, who is more movement based and runs in behind, or a ball to feet winger who can 1v1 the fullback and stretch the game as a ball handler, similar to Yamal and Dembele of the past.
Having the imbalance on both wings where on one we have a ball carrier and dribbling threat in Yamal and on the other we have a winger attacking the space in behind has actually worked really well, especially in Flick's first season. The matchups Yamal can create with his threat allowed Raphinha to attack in behind and finish off chances.
But in PSG's model, they have ball carriers on both wings and up front in Dembele, Kvara and Doue which allows them to consistently create numerical superiority in attacking situations, since their forwards are so good at drawing players out of position with their dribbling. However they don't have a forward who is as strong off the ball so they often score very individual goals, cutting and shooting etc, they don't attack off the ball as much.
Nico and Barcola would be an example of wingers who are more ball to feet. Nico is mixed type but he generally does his best work when he can take on players. Similar for Barcola. So we would have two takeon threats wide and ideally we would have a player that can attack the centre of the pitch and take advantage of the space they create. More similar to Raphinha are players like Lookman and Rashford (but Rashford's intensity is nowhere close which makes him a bad fulltime replacement). Its hard to find a like for like so we might have to opt for someone with a different style although names are limited. A good idea could be, if he leaves, to sign one proven forward and one young/developmental player who might pay off like Godts (need to look closer at him as haven't watched him before). Yildiz would be a good option but Juventus will probably not sell below 90 million or so.
It also occurs to me that the news that the club is looking for a new winger would also make sense in light of this news, although the names proposed like Abde, Rashford and Virgili don't rise to the level of replacing him.