The current videos for MD-101 are still relevant, This is why we are updating the other Microsoft courses first, they have more significant changes.
Most of the changes to MD-101 from the previous update were based on name changes, Office 365 -> Microsoft 365, and the changes to the names of the Microsoft Defender suite of products.
The changes being implemented on May 25, 2021 are minimal. There are two. They changed the name from Microsoft Defender Advanced Threat Protection to Microsoft Defender for Endpoint. They also removed the sideloading of apps objective.
You can see the changes to the objectives here...
So while we are going to update the content, the current content is still relevant.
Hope this helps,