New Feature: Video Comments for PDFs now available on Edge browser

Microsoft Edge version 90.0.817.0 (Official build) canary (64-bit)

you're going to need to enable this new flag first:

edge://flags/#edge-video-comments-pdf

You can add .webm format videos that are hosted online(like OneDrive, GDrive etc) to PDFs as comments. Edge will support inline playback of these videos. (Note: Users should have permission to access the video(URL) to be able to view it.)  

available on: Mac, Windows

I added a 1080p mp4 file. you can move the video comment to anywhere on the screen, also can watch the video comment in full screen.

Very nice feature in my opinion.