I did ask and receive clarification last year, or a couple years back maybe (time flies), on the situation where there is a concurrency of Class A and STW (Stocked Trout Water) on the same stream in the same county, but different stream sections.
Using Northkill Creek, in Berks County for example. It is on the Class A list in its headwaters in Berks County...Headwaters to Northkill Rd. bridge. The whole stream is listed as STW in Berks County, and is stocked further downstream from the Class A section...Feick Dr. bridge to its mouth. It is not stocked in the upstream Class A section. The explanation that I received is that for purposes of fishing from March 1 to Opening Day, the STW regulation trumps the Class A designation, and the stream is closed to all fishing in the county of the STW regulation during that time period, including the unstocked Class A section.
I saw this new language in the STW section that I didn't recall before that I believe covers the above scenario:
"Unless geographically designated in the Region Regulated Trout Waters section, the term trout-stocked waters includes the entire stream from headwaters to mouth."
^ I think this essentially is to differentiate stream sections within the same county that are listed under different regulations. For example a STW that is adjacent to a FFO or other open year round regulated section on the same stream in the same county. Class A is not a "regulation" per se, it is a biomass indicator and management designation.
Short, bottom line version for the OP: If the stream you're looking to fish is listed as a "Stocked Trout Water" in the regs book in the county in which you're looking to fish it, it's closed from March 1st to Opening Day. Class A or Wild Trout designation doesn't matter.