The on-sale date is from the publication date recorded in the Catalog of Copyright Entries, Third Series, Vol. 1, Part 2, Nos. 1&2, Periodicals, 1946-1947.
Chronologically, the next All-Winners Squad story is in What If? (Marvel, 1977 series) #4, which retroactively establishes that the post-VE Day Captain America and Bucky are actually William Naslund (a.k.a. The Spirit of '76) and Fred Davis. It is possible that this retroactive continuity actually applies since issue #16.