Despite every manager wanting all their signings in before pre-season, it's often quite difficult to do that. Remember there are 3 parties with their own interests involved. The buying club, the selling club, and the player. Take Gravenberch for example, he's clearly someone we like, but Bayern are not not looking to push him out the door and if there is no chance they'll let him go unless they bring in a replacement. And if they actually decide not to bring in a midfielder and tell Gravenberch he'll play a far more prominent role next season, chances are he won't be interested in moving on. Maybe Nice just point blank refused to agree a deal on Thuram until after the Euro U21 because they want to see if he has a great tournament and it flushes out more interest in him and they can get a higher price. Or maybe they want to sort out their deals first without selling clubs pointing to the £40mil that just landing in their account. Then there is the question of how wise it is to sign a player before he plays a whole bunch of games in short period of time for his country. Kone got injured yesterday playing for France U21 and was on crutches. Didn't look great. We'd all be feeling pretty shitty if we'd already signed him and now he's out for a year.
Bottom line is unless a club is actively looking to sell, and the player is actively looking to move on, transfers are quite complicated. And also, no one, not journalists, not random Twitter, actually know what is going on behind the scenes at the club and what Klopp and the recruitment team are thinking. They may get the occasional bits of information from agents, or get fed certain things from clubs that the clubs want out there, but that's it really.
As players start coming back from holiday in time for pre-season, we'll start to see more movement I think.