Doesn't ring true to me, but the only real test of this premise will be how hard they will try to hold onto him in the face of declining results (and consequent revenue). If the board really doesn't believe in sustainability, let's see them a) pay a premium to remove Wenger, b) expend money to recruit and c) make substantial (unsustainable) funds to back their new man.

I see them as being highly resistant to this, Gazidis' flat refusal to consider sacking, suggests this.
Agreed, I see nothing changing whether Wenger stays or goes, maybe bar the usual, temporary bump gained when a new manager arrives. The facts of the matter are simple and yet almost completely ignored. The board has consistently failed to invest in the team. In fact it's worse than that, they have run down the team in a series of disastrous transfer windows. Whoever was calling the shots (let's face it, like any other company in the world it is the board that has the final say), the buck stops at the top. But the ultimate and damning indicator of who is most to blame for the demise of the team is spelled out clearly in the huge amounts of money the board members have personally taken at the very same time the team was descending into chaos. So many overlook this glaring point even though it is staring them in the face. This club is now in the hands of corporate rapists. They talk of sustainability and financial prudence, yet we cannot sustain even our 4th position in the league. Then again, they haven't been interested in sustaining the team for a long time now, as successive transfer windows have shown. But they managed to not only sustain but enhance their share value for the whole period up until they cashed in. This is why I'm sure they would say they have presided over great success. From their point of view it's hard to argue. Virtually zero money in and hundreds of millions taken out with a clean escape beckoning in time to avoid the ship sinking. They've done very well for themselves. I hope they die.