Who I have the same questioned this solution

You won't get an answer other than for them to point you to either their news page: Verizon Wireless News Center

Or to the supported WiFi Calling device page: Smartphones | Verizon Wireless

Could be their silence on the issue means that all 13 phones that currently have WiFi calling is all the current phones who will get WiFi calling. I would love for them to give a solid answer on if those phones, like phones from Motorola, that are not currently listed will ever receive WiFi Calling. My guess is that they are only activating WiFi Calling on their flagship phones and everyone else, including those who recently bought phones will be left out in the cold. The WiFi Calling will be a selling feature to a select few (probably more expensive) phones.