I would agree on this as well. Since these roads are a must, but are 2x2, they're literally a waste of space with no happiness bonus. A piece of Promenade gives 35 happiness, double it and you'd make 70. I'd agree on 80 happiness, as Falcon has said above, simply because in my opinion bigger buildings (as roads still fall in this category) should give a better outcome.
We already get enough size-changing buildings with each age, especially with IndA and now PA, plus the 2x2 MUST roads, to have them give literally nothing. I really hope this is at least put under consideration.