Go read your link carefully. Page 23 not only does not disallow network access, it specifically allows logging it and stipulates what can be done with that data

Go read your link carefully. Page 23 not only does not disallow network access, it specifically allows logging it and stipulates what can be done with that data. “ keystroke logging done by any such extension must be clearly disclosed to the end-user prior to any such data being sent from an iOS Product, and notwithstanding anything else in Section 3.3.9, such data may be used only for purposes of providing or improving the keyboard functionality of Your Application (e.g., not for serving advertising);”