This article does seem to report different numbers - 47M instead of 100M.
T-Mobile Confirms It Was Hacked - https://news.ycombinator.com/item?id=28202399 - Aug 2021 (248 comments)
T-Mobile investigating claims of 100M customer data breach - https://news.ycombinator.com/item?id=28192423 - Aug 2021 (191 comments)
This article does seem to report different numbers - 47M instead of 100M.