In very broad brush strokes then it is a starting point but again we will see in March. Not a normal situation as there is no top end card from AMD so the number system could quite easily be shaken up.
I have no skin in this game and it is just an opinion. I hope they put out an amazing card and manage to keep the price low as it will be good for everyone. It doesn't seem they even know what to set the price at yet so it's going to be interesting.
Model numbers serve as a signal to the market. AMD will not launch a card that performs and priced at the top of the market and give it a mid-range model number. They are already telling everyone where this will land with that model number. Now to your point, there is no top end card, so this may well perform and be priced slightly higher than prior gen 7700, but will be in that ballpark.