There's considerable information about why the thread was closed on Discord. In sum, somebody thought it was promoting a commercial product.
That is 100% silly and wrong. It's no more commercial than the SFX shield board. This is how the community evolves, with many folks contributing their expertise and ideas. The amount of useful info in that thread, including setups and ways to reduce EMI noise, was immense.
I don't know who reported that thread or was offended by it, but this action by RD is a disservice to the community. Further, for those of us that spend considerable time contributing here, I'm much more reluctant to spend the time to help others, if the result is it will be wiped-out by someone in a capracious decision that erases hours of hard work. Come on RD, do the right thing and restore that thread. At a bare minimum, allow us to recover our tutorials and write-ups so we can repost it.