Dembele was often to says he want to staying at Barcelona before and previously there was a Arabian club who want him and he was decide to refuse the offers from that club and actually PSG was targetting him since since a few months ago but i thought the negotiation will never be happend but PSG has been showing that they were very serious who want him so maybe that's why Dembele will starting to considering moved to PSG and according to the news Dembele has release clause 50 millions and this want to utilized by PSG to gets him and reported Dembele and PSG currently has personal agreement and Dembele will accept 5 years contract duration and apparently in the near future this transfer will be happened
It's really crucial for Barcelona because they only have Raphinha who's can play in right winger position and he's not good as Dembele. This is not good, Raphinha will be forced to play as a starter and Torres will become a substitute player, Barcelona's right winger isn't solid enough. They need to find a good right winger player to secure their trophy for the next season. Will Barcelona sign Antoine Griezmann?
I do not think that Barcelona would care. First of all Rapinha may not be as good as Dembele but he is more available, Dembele keeps getting injured all the time and it hurts their chances and makes Rapinha not be ready for it. If they sell him, they will both make a lot of money, and they can get another player there instead, or they could just fix the debt issue and the cap issue at the same time and do whatever they want.
Dembele is French as far as I know, and him going to PSG would make him better, and he will probably play more there, and PSG would have a right wing to replace Messi, sure maybe not as good, but at least younger and could be good. This is why this deal would work for everyone all at the same time.