There's hardly any point unless they make it [AWD/LR] significantly cheaper than the P version [without PUP]
Why would they? Since the cost difference is zero for them, making the AWD LR a lot cheaper is just asking for lower margins on the cars.
In the Continental Europe configurator, it's not the same, since we can't buy the P-, only the P+ (P with Performance Upgrade Package complete with 20" rims and matching tires).
I would suspect that (depending on the response in the UK to the P-) continental Europe might also move to an SR+/(LR)/P-/P+ r ange as well, with the RWD/LR off-menu and the LR AWD replaced by the P- at only a slightly higher price. I suspect discouraging/encouraging people to buy the RWD LR would depend on exactly how many front motors they have in stock ;-). There are always rumours of impending demise of that model but the stubborn demand for that original model 3 flavour is keeping it alive and well.
The option that would make sense between the SR+ and the P without PUP is the RWD LR (since at least there is one less motor, and some people would find the slightly longer range interesting on its own).