I don't think they have plans. For starters, like most most mmos, they most certainly have a ToA clause that informs the user that (in very short words here) that you agree that there might be service disruptions and that they're not liable for it.

That being said...

Many mmos compensate not out of obligation but rather goodwill and subtle attempt to retain your patronage. There are various degrees at which they do this. Typically, a complete inability to log in, much less even play for an entire day may lead to an extra day or days of free game time. Notice the "entire" here. Anything less than that and its usually something like double exp or some consumable goods or very low value trinket.

All in all, the keyword here is obligation, to which SE usually finds itself not having to adhere to.