After recent development environment upgrade to 10.0.26 release, I noticed when I compile any D365 project containing label file, the label IDs in the file get re-ordered alphabetically. This is a new out of the box feature added by MS probably to enhance fetching labels.
If you want to turn this feature off/on in Visual Studio, Open Options menu by navigating to Dynamics 365 > Options…
Click on Projects tab under Dynamics 365 menu. You will see a new option added:
Order labels in label file by their ID
By default, this option is enabled.
AZ on D365 