He's been under proper pressing only few times, tbf.
The problem is: put Rakitić in this match with so much space and he'll look at least as good if not better. But, at the same time, prime Xavi wouldn't look much different either. So it's impossible to tell.
I'm really interested how this pans out.
Let's see how he'll carry himself under real, heavy pressure in midfield. His ball retention looks stellar, but the opponent are completely hapless in these vids. Either they come at him in slowmotion or pressure him one at a time, letting him brush them off easily.
Again, his skill set looks perfect, but I won't get myself carried away just yet.
IMO when assessing Arthur it's not so much about the quality of teams pressing him. You can see even in that comp that he gets challenged and pressed up on multiple times a game.
The part that's much more significant is HOW he reacts when he's pressed, or when he has to play through pressure. He shows great awareness about where the defending bodies are on the pitch at all times, and knows how to evade them and move the ball where it needs to be without fear of the players closing down.
He also consistently splits defenders with passes EXACTLY the way I would want a Xavi-esque midfielder to do. It doesn't matter so much if he's going through 2 no names from Brazil or Modric-Kroos, the space between them is still there and playing a crisp pass like that between them won't get intercepted 9/10 times.
It's the quality to make that pass accurately and the willingness to do it despite the defenders' presence that's key. On top of that, he's excelled at every level of competition in Brazil even at the highest tier. And, from what I've seen in videos/stats, he has a lot of energy and defensive tenacity too.
It's hard to outright bust when you've got the athleticism/energy and all the right instincts/skills as a player. I find similarities between how NBA scouts look at college players (who are playing at a MUCH worse level of competition compared to the NBA) and how football teams look at players in shit leagues. You want to see them succeed at a lot of the things you'd expect of them in your own team, and have a good athletic profile that can translate to more intense competition. Fit is more valued than outright quality.
I think, at worst, he'll be a serviceable player that doesn't turn out to be as visionary/excellent as we'd like him to be. In the past 7-8 years, a midfielder who proves to be a standout talent in the 'Xavi' mold has a very low rate of failure. The only ones I can think of in recent memory are Oliver Torres and Samper. Both of whom had many questions early on about their physical abilities and stamina. Samper lacked way too much mobility to ever play like Xavi and he's caught in the Busi role without good defensive qualities. Oliver still to this day is an impressive/eyecatching creative player but he lacked the physical strength and stamina to truly break out.
Modric/Kroos/Thiago/Isco/Verratti/Koke/etc. have all excelled after making the move to a big club with an important role. The magnitude of success varies, and while none of these players are 'Xavi' they are all high quality and would've improved our squad by a LOT in the last 4 years.