Yes

Is Microsoft Purposefully Degrading/Crashing Internet Explorer to Bully Users into Upgrading to Windows 10 & Edge?

<Tin_Foil_Hat>
Of course they have.

Haven't you noticed that your computer slows down following the upgrades that Microsoft releases when a new OS comes out?

Do you think that a browser would be a bridge too far?
</Tin_Foil_Hat>