Did Joseph Smith publicly deny plural marriage?

Yes. Joseph dictated the Whitney sealing instructions in July 1842. The paper he edited reaffirmed monogamy that fall.

The dates put the private sealing before the published rule. Joseph’s responsibility as editor is clearer than who wrote the specific editorial.

The paper must have come out before Joseph took any plural wives.

Compare July 27 with the September and October issue dates. The sealing predates both issues.

Yes, that is the qualification in his journal.

The qualification is visible as an insertion in the later draft. Richards’s entry stops at “one wife.”

That wording comes from an addition in the later history draft. Richards recorded the one-wife instruction without it.

You distinguished a contemporary entry from the later compilers’ interpretation.

The surviving full account is a later draft likely based on Bullock’s notes. Bullock was present, and he later edited the draft.

That gives the report a connection to an eyewitness while preserving the limits of the surviving text.

It is from a verbatim transcript certified by the court.

Joseph said it in a public sermon about accusations. The surviving draft was prepared years later for the Church’s history.

Anyone who heard it as a denial of religious marriages misunderstood the whole thing.

The sermon never makes that distinction explicit. A reasonable listener could hear it as denying the private sealings.

It explains one possible reading. I can still see why a listener would think he had denied the religious marriages too.

That answers the concern about public meaning while leaving room to examine what Joseph understood himself to be denying.