and Vrak posted here in CS too.
With regard to credit - Maint is factored into the price we already pay and is expected. The game does not have 100% up time and never has.
They HAVE given credit before for really unexpected long down times. That happens after the down time is over and they can assess the impact of it. If the Devs decide to do it, they will then credit everyone game time. It has been a long long time since they did that though.
It usually takes multiple days of down time before that kicks in. We had that in Vanilla and the early days, but it rarely happens anymore. I think the last was WoD release.