I can't imagine how the game would still be inter-operable after 50 years of even careful changes, unless none of those careful changes amounted to any shifts of the sort that could reasonably be described as "innovations."
And barring, like, Chess and Go, most of them are barely played.
Well, Call of Cthulu, which you brought up, is a great example. CoC 1E and 2E from the early 80's are fully interoperable with 7E from the Teens, but you would find if you look at the books that plenty has changed. And for the better! Both the careful change, and that it has changed, are a big part of why CoC is still a dominant game in the hobby.
Yes, barring the ones that are frequently played...
Well, as far afield as it getting, it is at least about the philosophical basis for how WotC is approaching change.
To be honest, we'll see if that approach survives testing.
I think even more so than unified subclass progression, this one left me questioning where the feedback is coming from on that matter. Are significant numbers of people really using their 200-word write-in sections to say "I noticed this word that isn't capitalized in the 2014 PHB is capitalized in the UA and I won't stand for that"?
I mean, I really wouldn't be surprised if they did, people can be persnikity. I spent too much time learning German, and then studying Medieval texts, so I don't even notice if random words get capitalized or not, frankly.
