Can I ask you this? Do you check your bag before you go on a stroll down the fairway, to see how many balls you have to play with? I'm not trying to be a A**h****
If you know you have 2 balls, but it's unfortunate we can't see how much life is on a ball before we start a game, and while you are on the tee you'll get that message, "1 hit left", "last ball remaining", and it'll be in red or yellow, I think. And either it's on the next shot, or next tee, it'll ask you to buy more balls. And that would be highlight in white.
Nonetheless, WGT send those messages when the ball you are playing with is about to die. So, you can have 10 balls in the bag, but when that ball is about to die off, WGT will send you that msg every time on every ball.
I hope I explained this correctly. TC