The betas page as we knew it, won't come back, but a betas section will be added to all the customers' accounts at portal when we have it ready. Hopefully, it won't take much time.
Regarding the problem with the Denoiser reported by Fox2, it's something that may happen when playing with Multilight in a render with Denoiser. As the changes in light could be affecting one of the passes but not the other, the result can be odd like you show. When you click Re-Denoise, the Multilight state is copied to both passes and the result is consistent. When combining Multilight and Denoiser, it's better to make the changes at the end of the render or make sure both passes have the same light intensities.
This is another part that should be improved.