If they are buying a combination of preferred at a $69B valuation and common at a 30% lower valuation, it is certainly possible that the overall valuation is a discount to the $69B. Hard to know without seeing detailed terms

I'm sure the liquidation preference (presumably 1x?) is worth something, but is it worth a 5-10-20-30% discount? At Uber's current valuation, the preferred would convert anyway so the liquidation preference would not be relevant

Edit: saw that the total investment is slated to be $10B, with $1B invested at the $69B valuation and the rest presumably in common shares at a 30% discount. It could be true that this does not represent a decrease in valuation, but there is reason to believe that the overall valuation is a step down. Devil in the details