My guess is that yes, this would work, essentially a receiver only.
You might be able to put empty reservoir on, but NOT do steps to load insulin.
Another option is to load xDrip on android phone, which will read cgm data direct from G6 transmitter.
You could also load the hacked version of G6 app, that works on non-supported android phones.
But if all you want is G6 with medtronic pump, leave tandem in box, and just use xDrip on phone.
And then add a watch that can display cgm data from xDrip.