The Patreon Bonus Moment is set in Step 3 rather than Step 4, so I'm not sure if that's what they were talking about. But if it was, there was still some confusion since it's content outside of the real game and not gonna be included in Step 4. It's understandable you didn't get it. We'll try our best to have the different elements of the game be clearer for everyone going forward.
The Patreon bonus content won't be available until it's done. There's no way to buy it before the release. Afterwards, it'll be up on the Patreon forever, or at least until the day the company closes and the Patreon is shut down. But ideally that won't be happening any time soon, haha.