My guess is they didn't publish it because they only measured it at one company, if they had the data across the cohort they would have published.
The general result that review/re-wrok can cancel out the productivity gains is supported by other studies
AI generated code is 1.7x more buggy vs human generated code: https://www.coderabbit.ai/blog/state-of-ai-vs-human-code-gen...
Individual dev productivity gains are offset by peers having to review the verbose (and buggy) AI code: https://www.faros.ai/blog/ai-software-engineering
On agentic being the saviour for productivity, Meta measured a 6-12% productivity boost from agents programming: https://www.youtube.com/watch?v=1OzxYK2-qsI&si=ABTk-2RZM-leT...
"But it's different now" :)