Not that I recall.

He mentionned it in Lector in Fabula (or at least in the same book this essay was from, in the edition I have), and IRRC in a late 90s essay I only know as Six Promenades dans les bois du roman, and again in his recent essay on translation, Eco elaborates on the idea that attempting to abridge Monte Cristo, cut down all its disgressions and redundancies would deprieve it of devices meant to slow things down, intrisically necessary to the very concept of revenge, following the saying that it's a dish best eaten cold.

He's mentionned Monte Cristo in several interviews over the years, though essentially he reprises the same core ideas from his original essay each time : "One of the most fascinating novels of all times/one of the most badly written novels of all literatures and times". He discussed it in one of his "three musketeers" conferences with Salman Rushdie and Vargas Llosa too - they debated his claim that it was a "bad novel" for a while.

At the time of Foucault's Pendulum, he had spoken of its influence (and in a more general way, Dumas's) on that novel, thought that's so long ago I don't remember what he said about that.

Once, he spoke of the likes of Dantès and D'Artagnan in comparison to Emma Bovary and Julien Sorel, but I don't remember in which of his books that was. Essentially, he was fascinated with the fact that you can take Dantès and D'Artagnan out of Dumas, that these characters were myth and had a life of their own outside the novels they come from, and can exist in other stories (and Monte Cristo and D'Artagnan have inspired many other novels), but that in comparison without Flaubert's words, Emma Bovary was just another boring provincial adultress and Sorel just another ridiculous fool never doing what he should do. That Monte Cristo and similar popular literature (which for him is a return to Homer or Sophocles) was fascinating for its power to generate a myth independent of the artistic quality of its vehicle, while works like Stendhal's Le Rouge et le Noir, or Madame Bovary, were "solely" works of art.

He speaks of Monte Cristo in 'The Art of Creating a Legend" piece e he wrote for the Guardian a few years back.