If you're talking about how it's listed like this, that's just because the official names changed.
The M1 iPad Air is officially called the iPad Air 5th generation. Apple changed the naming convention with the iPad Pro (M4) and iPad Air (M2). The M2 iPad Pros are called the iPad Pro 12.9-inch 6th generation and iPad Pro 11-inch 4th generation.
Going by your logic, only the iPad Pro (M4) will have more apps open while M1 and M2 will only have 4 apps which is unlikely.
iPadOS 26 supports the following iPad models:
- iPad Pro (M4)
- iPad Pro 12.9-inch (3rd generation and later)
- iPad Pro 11-inch (1st generation and later)
- iPad Air (M2 and later)
- iPad Air (3rd generation and later)