We are currently experiencing delays with our email service, which may affect logins and notifications. We sincerely apologize for the inconvenience and appreciate your patience while we work to resolve the issue.
The only two features I can see are lack of a messaging app on the phone, and lack of an email app on the phone. Those two things are tied to Samsung phones.
But you can still text message from the Galaxy watch no matter what (from Contacts), and you'll still get your email notifications. My wife uses her Watch with a Moto phone, no problems.