I had this issue back in 2013 so I have very little idea what's the current situation, didn't change my icon pack since then, however before I wrote the post I did check archive.org and it seems like last update was around 2011, so nothing's changed since then
The 0.8.90 is also wrong, since then there've been some changes - diff:
+ system-reboot The icon used for the “Reboot” item in the desktop's panel application.
+ user-available The icon used when a user on a chat network is available to initiate a conversation with.
- user-online The icon used when a user on a chat network is available to initiate a conversation with.
Freedesktop.org is kinda bad at showing that it isn't a dead organization.