Should LR be checking XMP/ACR (Metadata files) for video files?

Windows 11
Lightroom 15.4.1

I have recently enabled ‘Automatically write changes into sidecar files (XMP/ACR)”  - mainly as a safety net in leu of other issues, but that is not relevant here.

It took a while for LR to complete the saving of all metadata files - probably 12 hours (259K files in the catalog).

I just loaded LR, edited one image in PS and saved. It appeared in LR and then I clicked CLOSE on LR. It warned me that Metadata processing was still busy. I checked the status and 843 files are being processed. The folder I have open only has 744 images.
I used Resource Monitor to check what files lightroom.exe was accessing - and it is lots of 
MP4/MOV/AVI files ... in folders unrelated to the folder I was viewing at the time.

I have repeated this and seem similar activity each time.

It’s not a problem - but i wonder why it needs to scan video files at all?   and why it does this regardless of the images I am working on.