I don't understand why people are toting current upgrade times as factors for new hires. When I was hired upgrade times were at 7 years. But growth was approaching and there were not a lot of people hired between now and then. So it dropped from 7-2 years in a matter of just 2 years.
In the last two years since I was hired there have been nearly 1400 people hired there. If you want my guess, the upgrade will probably be 4-5 years for someone starting at OO now.