I think it is unlikely for some clubs to keep some players with injury habits, even if it is a top player. One of the reasons for this transfer may be that PSG themselves do not want to waste too much time paying him but they cannot get the full contribution from the player, as we know that Neymar has a high salary there. And then this deal is the right option that PSG has chosen by selling it to an Arab club, PSG has earned a lot of money in this deal amid their problems with Mbappe who still hasn't found a bright spot. Now Neymar has become one of the Arab club players with a salary that will certainly be fantastic, regardless I hope that he can find a way to minimize the chances of injury and then meet the expectations of his new manager there.
I see it as the right moment, because PSG will lose more if they don't let Neymar go this summer. Because PSG recruited him for a fantastic price in 2017, his departure to Al Hilal will cover half of PSG's expenses when he brought him from Barcelona. In line with your point, that PSG has taken the right steps towards Neymar, frequent injuries and inconsistent performance have made PSG speed up releasing him when the price is still expensive.
Entering the age of 31 is very suitable for Neymar to play only for money, but on the other hand joining the SPL will have an impact on his position in the National Team.