What, if any, is the impact on this site, the addons, and the addon client? Are these part of the sale?
Shouldn't be any, but we have not been told anything. It remains to be seen is if addon authors will continue to be paid. We have not been able to get paid for over a month now, so who knows.
CurseForge isn't part of the sale according to this: https://twitter.com/CurseForge/status/1073364253246144512
However, in another tweet: "We will be using medium for the central source and all sites will link to our medium articles :D These recent posts should have syndicated over, but we will be fixing that issue soon!"
and then there's this: https://medium.com/curseforge
So hosting might be an issue.