Your docs contribution going missing:
We were forced to remove some contributions, because we needed to relicense the docs.
We tried for months to contact all contributors, so when the deadline came, and passed, and came again we finally removed the contributions that could not be relicensed.
We also currently have a slump in docs contributions, they need a lot of love.
As for your programming query:
“it matched the request for an Entity type as Player is a subtype of Entity.”
Player extends / implements Entity.
If you ask for the first entity, you get the first entity, even if it happens to be a player.
But shouldn’t it have the type Player?
No, if you ask for an Entity, you don’t know what subclass you are going to get. It could have been a Zombie in a different example.