The description of the stove as "self-pressurising" isn't hype. That is an accurate description of how it works.

Sure, the stove eventually is self-pressurizing. You needn't tend it constantly to maintain its pressure. Hoever, I still think this description is somewhat misleading. One cannot simply tell the stove "pressurize yourself", it requires your assistance, IOW, priming.

A less misleading description would be "self-maintaining pressure". But that is awkward and does not make very snappy ad copy.