1. Using the AWS cost calculator is pointless, naturally an entity the size of NASA would get heavily discounted rates. 2. As data volume grows, the complexities of working with that data expands. NASA appears to be embracing cloud computing by embracing a paradigm where scientists push computation to where the data rests rather than downloading data [1], [2], [3], thereby paying egress on only the higher order data products. 3. The report notes that NASA has tooling to rate limit and throttle access to data. This, in itself, proves that NASA didn't "[forget] about eye-watering cloudy egress costs before lift-off".
People may scream about vendor lock in, which is a fair complaint; but acting like NASA just didn't think about egress is misleading.
NASA is ultimately a science institution, I think diverting effort away from infrastructure management and towards studying data is likely a wise decision.
[1: https://www.hec.nasa.gov/news/features/2018/cloud_computing_...] [2: https://link.springer.com/article/10.1007/s10712-019-09541-z] [3: https://ui.adsabs.harvard.edu/abs/2017AGUFMIN21F..02P/abstra...]