No they wouldn't.
But that doesn't mean that other clubs with more financial means wouldn't have paid that amount, and then some.
And again, if Bayern was the ONLY club that Vidal wanted to go to, what do you do? Do you go against your public word when you said that a player will only leave if they are asked to so that you can make more money on his transfer? Make yourself out to be a hypocrite?
Do you respect and fulfill the player's wishes?
And if you don't, what message does that send to the rest of the team who witnessed him sacrifice so much on the pitch. Selling him off to Arsenal for 45mil would have been a slap in his face and the players left behind would have even more than a cattle mentality.
And Juve wouldn't pay 40m even with the luxury of already knowing how well he fits into and performs with the squad. Bayern and others know none of that and thus are taking on a greater risk.
Not to mention that there are probably more of his best matches behind him and not ahead of him. On the pornstar career trajectory analogy, Vidal isn't doing interracial S&M gangbang films yet. But he's growing in tattoos, he's getting banged by the occasional black dude, and he takes a DP every now and then. That's where his career is at right now.
Ok, I get people are mad and upset over change that's inevitable. People wanting to behead everybody like IS soldiers once Del Piero left for example. But please get this out of your systems quickly. It's ugly, it reflects a lack of emotional maturity, and it's unbecoming of a historical juventino.