Oct 2017 echo calling (new version)

[gsuemnic]

The Oct 2017 upgrade to echo calling is great, being able to call any contact or phone number without the other party needing the alexia app.
HOWEVER;
In order to get it to work on my elderly parents echo, it required the removal of the alexia app on my phone, which I used to drop-in on their echo to check on them   (Yes, their echo is registered to their own cell phone)

If I re-install the alexia app on my phone, in order use the drop-in feature again) will they still be able to use the new Oct 2017 version of 'echo calling' to call me and other without the Alexia apll or will the original calling version take over because I'm a contact ?

I ask because a month ago it took me many calls to support to covert their echo from using the original version of calling that required the Alexia app on my phone, their echo kept saying
saying "Call sons mobile" and then the green circle would spin & spin, while my phone just sat there. 
During the trouble shooting nightmare I was told to remove the Alexia app on my phone.  Several hours and more calls to support later , it stated to work, but of course removing the app on my phone removed my drop-in capabilities.

Sort of afraid to re-install the app on my phone and undo the new calling version

A recent call to support yielding no clear answer what would happen, sort of got a scratching of the heard response.

Thanks in advance