Seems a bit premature to assume this was the vector used for those other breaches.
That other product/service was compromised, which let hackers hack into MS employee’s computer, which gave them access to Azure infrastructure.
Lesson: ask your (in this case Microsoft) employees to not use work computers for any personal use.
/me goes to check if my password manager company uses Okta.
This is just wild speculation to make up a scenario where Microsoft could be affected by the Okta hack with no evidence to back it up.
I was just trying to come up with a threat vector to explain how it might be possible.