AWS have already calculated the pricing model of lambda to take advantage of this massive inefficiency of their lambda product, they charge multiple customers simulatnaeously to use for the same hardware for the compute that would otherwise be sitting idle 95% of the time due to Lambda's basic design.
If large numbers of customers start using this model to reduce AWS' ability to double-dip, it's going to severely affect the profitability of Lambda, I wonder how AWS will respond?
But a naive increase will punish the majority of customers who aren't yet using a similar efficiency mechanism.
My guess, if this approach becomes popular - we'll see a whole new layer of complexity added to Lambda pricing making it even harder to estimate lambda costs ahead of time.