There are 4 statuses.

Green checkmark (status 0)

Green checkmark with "info" badge (status 1)

Yellow triangle (status 2)

Red "do not enter" rectangle (status 3)

I suspect that status 0 indicates that they are investigating a problem with the server, and it switches to status 1 once the problem has been confirmed.

This is also a good example of poor icon design...they aren't self-explanatory, and so they should not be used.

What happened to status 2?

Good catch. Fixed!

Thanks!

Because checkmarks make everything look fine...

Non-snarky answer: They want to post that they are investigating an issue, but do not want to comment on the scope of the problem when it is still not fully understood.

They switch to white-triangle-in-yellow-circle when they find out that there is a real problem. They just switched.