Rather, they are becoming the old Microsoft. Are you sure they aren't becoming the new Yahoo? Also, what new thing is the new Microsoft?
Nadella has changed the course of that staid ship by changing the underlying culture, no small feat! Some specific actions: Microsoft Office on iPad and Android, going all in on cloud (Azure has 22% of the market, ahead of GCP's 7%, at the start of 2019), being friendly with Linux (Windows Subsystem for Linux - WSL, exFAT specs were released a few days ago), given up Windows Mobile (he “did not get why the world needed the third ecosystem in phones”).
https://www.inc.com/scott-mautz/microsoft-ceo-satya-nadella-...
https://qz.com/work/1539071/how-microsoft-ceo-satya-nadella-...