User Page Discussion Count differs from discussions user's able to see

> I didn't really know how to name this, sorry.
## PROBLEM

Whenever someone deletes the first post of a discussion, another user can still see that discussion as part of the discussion count on the user's page, but whenever they go to see the actual list of discussions, it says there're no discussions there.
## STEPS
1. Create a discussion on a user's account with no discussions
2. Delete the first post in whatever account
3. Log out or login into any other account which doesn't have permissions to see deleted posts and/or discussions
4. You will see it says 1 discussion but shows none

The issue names no files, tests, or entry points. Reproduce the listed steps, then compare how the user-page discussion count is calculated with how the discussion list filters deleted or inaccessible discussions. Done means both views report the same number for users who cannot see deleted content.

Written by the indexing model from the issue text.