From DJI's perspective the Inspire 1 is 'end-of-life'. (i.e. no further development)
'Obsolete' would be the term to use come the day that parts, accessories or consumables are no longer made available by the manufacturer. As to when DJI makes that call, no idea but I doubt that they would cease parts support that early.
What we need is someone to start refurbishing TB's with new cells, props and such we can get aftermarket. Motor bearings can be swapped out. Then as long as you don't crash, you'll be golden for ages.