Remathilis
Legend
I would define a retroclone as a rulesystem which replicates an earlier, out-of-print rules system and adheres to that previous rules system as close as legally possible in order to preserve that system in some kind of evergreen format.
It's the underlined portion that disqualifies Pathfinder and C&C in my opinion. The "preservation" aspect of those systems is diluted by an effort to improve on the predecessor systems. True retroclones like OSRIC, S&W and LL (for example) are 100% about preservation and differ from their predecessor systems only where it's legally necessary.
A new term that could encompass all the "clones" as you define them as well as "sympathetic kin" (C&C, BFRPG) would be appropriate, but I doubt any term like this will come about, so I think "Retro-clone" is going to either become an incorrect big-tent label or its going to have to force some form of "purity-test" to weed out the true-clones from the sorta-OS games.