If an individual employee is going to put all that work in without being asked to or being given scheduled time to work on it they should get something in return.

Unless they were asked for, no? You aren't a snowflake and you aren't own praise for something you weren't asked to do. Maybe you work is great and valued (gold star), but your point of being owed something is just a bald face lie to yourself.

In the above scenario, I do not understand what they are getting in return.

Are you saying this person should be hired/paid to store and retrieve the information being sought out?

Being as you put it the "gatekeeper" advertises their importance to everyone in the company who needs to know about the processes, making advancement easier and guarding against anyone thinking they are not necessary.

Maybe more like the font of knowledge?