It depends on what's written in there. If the specs are not public, than that's it, and the manufacturer is the only one that can decide that.
I work with a lot of chips which include such rules in the NDA. Some of them don't exist at all, even if you ask the manufacturer and show them a picture of it, with their logo on the package
So there's nothing unusual here.
You know the architecture is single core mipsbe, backwards compatible with the older Atheros chips (we actually run the same firmware on them) , and the WiFi is a/b/g/n with 2 vs. 3 chains. More than that is probably not public.
RAM is external, clock speed is known, at least two gigabit ethernet interfaces are present.
More than that is of no importance to the mere mortals (but I would assume it is actually the exact same core and features, with minor differences in the wireless part, otherwise it wouldn't use the same 955x series number, as the last number usually indicates a chip subvariant, with differences in terms of included peripherals).