Interesting...
Personally, a very big reason why I don't choose P2P LCC's and prefer connecting via ATH is that I am able to select an exit row seat for free from A3. If I need to pay 30 euros one-way for a seat reservation, I might as well change my seat preferences...
Also, not giving at least some premium seats to M+B gold is a bit petty.
However, maybe when OLCI opens all seats can be selected for free by M+B golds, and nothing changes vs today, apart from taking away the free seat reservation benefit away?