While iOS is an umbrella term, the App Store is pretty clear about which devices an app supports. The device range is explained right beneath the screenshots, and the Compatibility section goes into more detail. In this case iPad isn't mentioned, so are you looking for some clear "no iPad" signal? If it will run on iPad, just not as a full-frame iPad app—because a few really won't run at all, like if they require a hardware capability only a phone has—how could they make that clear? In the storefront signal-to-noise game, is it worth the attention?
It's still one iOS SDK. As a developer and power user audience, we remember when iPhone OS was first renamed to iOS on iPad's release because they were the same. It hasn't been renamed back. Regarding usage, the term iOS development within Apple dev shops still refers to both iPhone and iPad code and App Store distribution. We generally use iOS as an umbrella term, and reach for the new term iPadOS in reference to the iPad-exclusive parts of the user experience like its multitasking capabilities and Universal Control.