Are the satellite features carrier independent?

Any iPhone 16 model phone sold today, will have access to Apple Satellite Services. But keep in mind it is really for emergency situations, where you have to access to cellular or Wifi services. Also note that in the US, T-Mobile has partnered with Starlink and they are offering a subscription to Starlink, even if you are not a T-Mobile customer for cellular service.

This may help you --> Connect to a satellite with your iPhone - Apple Support

And yes, carriers may have their own partners for satellite service, so if you are interested to know about their satellite options, it would be best to contact them directly.

Did you read the link that lobsterghost1 provided? Most of the Apple satellite access is directed through Apple services, not the carrier, but there are carrier specific services as well. There are additional links in the document that lobsterghost1 provided, but you can send emergency messages, etc. without carrier features. If your carrier was clueless, then I wouldn't think they are providing anything. But the features that Apple provides are explained in that document.

Why don’t you list the services you’re interested in and the country you’re in?

In the US, satellite service is still in beta form from the major carriers. T-Mobile is currently offering a beta version and a friend told me Verizon started an invitation only beta program very recently. I’ve not verified the Verizon availability. AT&T is a major investor in a service and is expected to offer at least a beta service soon.

Apple’s Worldwide Developers Conference is just a month away and who knows what may be announced then. 😀

Who is your carrier?

I would not expect advanced features from a discount MVNO like Mint.