I'm curious if this will also lead to an integration or update of google's voice feature (allows you to call people for free through your gmail) and google hangouts.

Shying away from web based texting works for security I suppose but I've known people completely ditching phone contracts and just use google voice to call or hangouts to text, all in one place as a quick example. Even I have been using sms messaging a lot less over the years, as I have my gmail open most of the work day(hangouts) and things like Facebook messenger, whatsapp, kik, for alternatives.

On the more secure side.. there are apps like Wickr that encrypt your messages for security. So maybe they can focus on something like that or security updates instead, with maybe some integration with google hangouts?