Source: Moh. Salah
Yea, I agree with what you are actually saying here, Arne slot hasn't brought in anybody now due to the fact that he is still evaluating the players at his disposal, and sincerely speaking, their are loads of talent in this Liverpool side which can still challenge Manchester city to the title if they are being handled by a very competent manager, so I wouldn't be that surprise if no new player is signed into this Liverpool team next season, because they have an abundance of talent in their squad already.
Then talking about mo Salah, I think if he moves away from this Liverpool side, he is definitely going to be a very big loss to this Liverpool side, and if something like that happens, they needs to replace him with someone more capable, that can fill the void left by the legendary mo Salah, but right now, he is still a Liverpool player, nothing is confirmed yet.
And lastly, it will be very good if Arne slot start training with his players very early, so as to know where the team is seriously lacking, so that something decisive can be done on that.