He specifically said that Giovinco could return to Juve, BUT, if he is in a system that requires tactical involvement in all facets of the game (i'm paraphrasing here), then it is best that he not go back.
This leads me to my hypothesis that he does not have the desire to come back.
Dont know italian nor how these comments are translated, but brief impression from reading that when it was posted somewhere was that the agent/Gio prolly referring to what happend last when he was with us when mentionning tactical involvement (random way to put it), played as LM in 4-4-2 under different coaches, coaches that preferred a hardworking and back-tracking approah out of the winger in their set up (hence why De Ceglie and Sali was played there over Gio eventually).
Besides being benched, role he played in was prolly what he didnt like about his time then (then under Ciro we got Diego so no room, also Gio wasnt ready to play as an attacker back then as he is now, bit out of his depth play that high up back then, quite assuredly more used to it now after Parma experience).
Someone should repost that annoying agents words, but I recall he said that his client prefers to be played as a striker/supporting forward. Which goes without saying due to the type of player he is, not only now even more when he as played as main focus for a teams entire attack in 2 seasons (or more like 1, first season for Parma was just a typical AM/fake winger). We play 4-3-3, a formation/approach that I said throughout the years suits Marchisio the most, while he was struggling in 4-4-2, because I seen him excell in that formation in the Azzurrini. The same goes for Giovinco, role/tactic that suited him alot, to be the left forward in 3 man attack way Vucinic is for us now, be given the freedom to both create and cut in to finish etc.
Added difference after last 2 years loan/co-owning is he also grown able to play in 2 man attack, playing off a box striker. Back then was tried there briefly in Azzurrini, and with Ferrara couple games, was defenitely not ready for it or able to cope (remember Lecce game, scored, but got intimidated by physical defenders too easily that close to the box), to play more of his back to the goal or closer proximity to the box.