Xavi is one of the players who have a crucial role in the success of Barcelona tiki-taka in Pep era. As far as I understand, there were 3 players who have the most roles at that time, they are Xavi, Iniesta, and Messi. S, if Xavi applied tiki-taka for the current Barcelona squad, it surely will be applied very well. Xavi knows very well about tiki-taka, and he experienced a lot as a player who used the tiki-taka strategy. In my opinion, the point of tiki-taka is teamwork and accuracy. It is about how the players can control the match by dominating the ball possession and creating as many as assists & goal attempts. This requires advanced skills in dribbling, delivering assists, and scoring. So far, Xavi looks quite successful to return tiki-taka to Barcelona players.
In the tiki-taka scheme, 3 midfielders must be very central to control the flow of the ball forward. Xavi and Iniesta were two very good midfielders at the time and they were so successful in controlling the midfield that the Barcelona forward felt very comfortable.
Xavi understood tiki-taka well because he was Barcelona's playmaker back then, but Xavi couldn't force his current midfield to do exactly the same as he did in the past. De Jong, Pedri and Gavi actually have a lot of potential to do the same, but while these midfielders haven't been at their best they still have a lot of potential to improve. If in the next 1-2 seasons these three midfielders are able to do something very good especially in terms of controlling the midfield with ball possession and accurate passing, then I believe Xavi's tiki-taka era will be repeated. So far things are going great, but still not perfect.