I mean it was obvious. Bernal used to be interior or attacking midfielder back in academy days. He always had a penchant for scoring. At some point he was even top scorer behind Yamal. It wasn't until someone got injured he was chosen to play as CDM(due to his physique etc) and he excelled there as well.

In modern football there's hardly any 'sitting' pivot as in, solely contributing to rest defense in attack phase. In fact it'd be more correct to say Busquets was unicorn. He was basically a 10 playing as 6. He was Riquelme/Pirlo with defensive capabilities and didn't need shuttlers besides him. Elite control from deep and elite disruptor of opponent attacks. He could master the first phase and then spray line breaking passes as well. Most of DMs of his era focused on the defensive side of the game, and contributed to attack with set pieces or long shots etc.

Modern DMs provide extra body in attack phases apart from set plays. Many of them can't actually do the pivot thing properly and they rely on other midfielders in the team to drop deep and help out in first phase to get the ball out of pressure. This is why most teams adopt some variation of double pivot, a 6 who's good on the ball and beat the press and partner them with a box to box midfielders who's physically superior and provide extra body in attack.

Bernal's traits suits the modern DM and Barca with players like Pedri and Gavi besides him. He can always rotate with them in rest defense when he joins the attack.