Let me be even more simple since we are making some progress.
There are two points of fact. First, God told Joseph and his inner circle to keep a secret (or so the story goes). Second, a doctrine was introduced and established.
These are two separate things, and both can happen at the same time, they are not mutually exclusive to each other.
The one I referenced, just as you quoted me correctly, was the introduction of doctrine.
Witnesses are provided when a word is established, not years later.
There were 3 prophets, seers, and revelators in the church at that time and all three never once testified of polygamy.