My understanding was that Microsoft had a specified timeline. Do you have reason to believe it's derived from Google's timeline?

If Microsoft says "100 days", saying "okay" instead of " no, 90" gives a timeline 100 days, not 101.

This is conjecture and frankly nonsense. If the time frame was 5 years, would MS really find a reason to delay and to publicly cry out loud? No. The only org being unreasonable is big G.