Can be!
Settings > Apps > choose an app > Lock Screen Appearance: Show Previews - Never
The message text is still sent to the push notification server from the app's infrastructure - this setting simply stops the phone from displaying the message.
The app itself must choose not to send the message text in the push notification.
The message text is still sent to the push notification server from the app's infrastructure - this setting simply stops the phone from displaying the message.
The app itself must choose not to send the message text in the push notification.