[3.x]: After adding a switch on dev and applying the yaml files site is ruined: all matrix blocks are now doubled

What happened?

Description

After adding a switch field to one of the matrix blocks of a matrix field that's used for content on each page and applying the yaml files to the staging server the full site is ruined by some 'propagating' action Craft does; all matrix blocks on each page on each site are doubled.

I don't even know how such a thing might be explained, but it's obviously pretty frustrating.

For some reason restoring the database doesn't even work (even when removing all cache and do a garbage collect). And now I don't even know how to restore this and if that's even possible without needing to change all 440 pages by hand :(
Which were all containing new data. I have regularly created backups of these, but the backup restore doesn't fix this issue, or fixes it to let Craft destroy it again by this 'propagation...' action?

Steps to reproduce

1. Add a switch to one of the matrix blocks in a matrix field on local DEV environment
2. Deploy the code to the staging server, which updates the yaml files
3. Craft does some magic making all matrix blocks now doubled on each page, on each site (also the many pages which aren't even using this block)

Expected behavior

No change on the existing entries, only adding the new switch to where this block is used and set it to the default value.

Actual behavior

See above

Craft CMS version

3.7.48

PHP version

8.x

Operating system and version

Apache

Database type and version

No response

Image driver and version

No response

Installed plugins and versions

Start by reproducing the YAML deployment steps on Craft CMS 3.7.48 with a Matrix field containing a newly added switch, then investigate the propagation action affecting existing blocks across sites. Done means applying the updated YAML preserves existing entries without duplicating Matrix blocks; the payload names no source files or tests to run.