BMW recommendation for auto trans is 100K miles. ZF the manufacturer is 50K miles. Who do you think I believe?
Unless BMW decides to warrant the transmission and diff for life they will be changed every 35-40K miles as per my previous BMWs.
All components are better as are the lubricants but they still all get contaminated or worn out and need replaced.
BMW does this for one reason, to try and keep competitive with Asian manufactures like Lexus who has long intervals for changes. Not product improvement marketing to keep pace with other brands.