I would imagine it is targeted at a similar audience, it just lets you answer a better question.

Given the current impression share for my campaigns, what would incremental spend do for CPA and position with 95% certainty?

What would be the expected CPA in 50% of cases to move from avg position of 1.8 to 1.4? This question can be asked in reverse again with a degree of certainty attached.

The answers to the questions you posted are likely to be averages and possibly medians if the posterior is Gaussian (or close enough). Mixing uncertainty into the equation allows you to provide a floor on probabilistic expectation, it also allows you to ask what the best case is, say the 95th percentile.

I've stuck to 95 and medians here but you can use any percentile you'd feel comfortable with.