Question

Hello Rabbi,
I heard in your lectures about conservatism, tradition, and innovation, regarding decrees and enactments whose circumstances have changed and there is no reason to preserve them exactly as they are. An example mentioned there, for instance, was the custom of prohibiting legumes, which doesn't seem relevant today. (I wrote this simply, in my own words.)
I wanted to ask whether the same can also be said regarding rich matzah on Passover, and permit eating it even for Ashkenazim.
I couldn't find a question on this topic in the responsa.