By the strictest of definitions, all gear is “borrowed power” in that the stats it give you is temporary until the point where you unequip it.
The new ring is borrowed power as much as any other piece of gear is with the level of power it gives you respective of your overall total power in question. In Legion, your “borrowed power” artifact was hugely responsible for your total overall power because it granted you a massively powerful ability and abilities that were akin to extra talents buffing you. BfA had “borrowed power” in your azerite gear pieces trading stats for effects (very similar to the ring now) and then later your neck itself coming with powerful effects too.
So yes, the ring is “borrowed power” insofar that it is meant to be a “significant” part of your overall total output capabilities with the intent that it will go away sooner rather than later and leave you with, likely, the same old boring stats again.