By "safe to upgrade" to 7.0.3, they mean that it won't hinder the ability to use some future 7 jailbreak. In other words, if you're already at 7, it's safe to go to 7.0.3 and you won't be any more screwed than you are now. ;-) If you currently have a jailbroken iPad, do not update to ANY version of 7.
Exactly!