According to [1], there are about 5500 people in Engineering at Uber. Using $1250 as the mid-point of the $ spend range, that comes to about $6.8 Million in engineering AI spend, ballpark, with the range being $2.75 Million - $12 Million. The article lists $3.4 Billion as the R&D spend.
The AI spend does not appear to be a significant chunk of R&D spending (0.3% in 4 months or 1% annualized). If they didn't plan for it, sure, it's not peanuts in the budget, but in context not that much.
The real question is, what did they get for that amount? The article claims that 70% of the code commit is now AI-generated, so presumably the code passed review and tests. Did it accelerate the feature count? did it reduce quality problems? Did it lead to other benefits?
Sadly the article is silent on the outcomes, besides the higher spend.
Maybe 4 months is too soon to assess the benefits. On the other hand, in an agile world ...