I agree with you that Discord should be independent of the ecosystem, the marketplace algorithm, and the free documentation as per ECLA compliance. As a buyer myself, I have come across products that have a Discord I have little to no interest in for my personal study but impedes on basic installation & use. Others on the other hand, have excellent optional documentation, videos, examples, templates, and experienced developers.
So, I still support developer choice when it comes to how they wish to support their customers & what means they wish to convey that support should be left up to them. Furthermore, after the recent decisions of Epic, sellers without a Discord or other 3rd party interest are almost completely disconnected from their customer base, which is not fair to their months/years of contributions to the marketplace & the community because it impacts their bottom line in the short/long interim. They know better than us buyers & Epic staff members how to support customers. They all have different logistical approaches to that goal. Giving them flexibility is not unreasonable, so I can’t fully support you declaring it a fallacy.
I want to see a future marketplace where verifications do not wash away legitimate Q&R, but I don’t want to see Discord taking over the marketplace either. I think a fair approach is the best approach in this case.