How extensive are those suggestions? Does each chapter go into detail? Do they name specific NPCs, factions and other setting elements as replacements for those from the Realms?
Having run PotA in Eberron, the suggestions were kinda half-baked. The groups they suggested to replace the factions were only passingly similar (if that), which means the hooks didn't actually hook. The bits about where to locate the adventure weren't horrible, but weren't particularly astonishing, either. There were problems with the map scale for that particular adventure (like, it was internally inconsistent) that gave me fits. Basically, that one was pretty easy to scrub off the Realms, but a bit harder to add Eberron flavor. I know Eberron well enough that I could adapt, but I did so by mostly ignoring their advice.
Tyranny of Dragons was considerably harder to convert. In fact, after trying to get ahead of the game while running the starter set, I just gave up. By the time I got done, it was more like I was using the same adventure outline, but totally different details. It probably would have been fun enough, but PotA came out and looked easier.
Curse of Strahd is explicitly in its own realm, so conversion isn't really a thing. I don't think the recommendations for hooks were good -- and really view anything setting specific as a waste for that book, anyway.
I haven't tried to convert any of the others, due to the speed we move through things. I don't think OotA would convert well. SKT might, though I've heard that it has some tight coupling to the Realms in a couple places. From what I've read, people have had very good success with converting ToA to use in Xen'drik or Q'Barra. I do not plan to even consider Dragon Heist. I can't imagine that it isn't tightly coupled to Waterdeep and/or that trying to Sharn-ify it wouldn't be at least as bad as ToD
Gamers have been scratching off the serial numbers of modules in specific settings for EVER - I seem to be misunderstanding why you believe this 5e module would be any different in difficulty to adapt?
Yeah. It's easier to remove setting-specific elements than it is to add different setting-specific elements. People who play in Eberron don't do it just because it's not the Realms. They do it because it's Eberron. Also, multiple small adventures (the old modules or Dungeon Magazine) offer more opportunity for interludes than the 128 page mega-adventures.