Juve's 4-3-1-2 was strange last season because the creativity came from Pogba and Pirlo.
You almost needed a non-traditional trequartista to make that midfield work.
With Marchisio playing as the regista, Juve are back to having a much more orthodox midfield three, so they don't need as defensively capable a trequartista.
However, with Dybala as one of the forwards, one can argue Juve would be better off with a trequartista that is more based on movement, rather than a classic creative, technical trequartista.
In theory, Pereyra should be a pretty good fit to play with Dybala and a centre-forward.
But I don't see any need for Juve to be particularly pre-occupied with trying to play 4-3-1-2 just now.