With PICARD-2170 the title and tracknumber fields guessed from filename when empty are treated as modified metadata.

The reasoning was that this data is not present in the file's tags and hence should not show up as original metadata.

However, the previous behavior was more useful. One can argue that this is still data from the files. Having this available for comparison when tagging the files with actual new metadata from MusicBrainz is useful. See e.g. the issue report at https://community.metabrainz.org/t/musicbrainz-picard-2-6-is-now-available/526853/23

The proposal here is to revert this change for the 2.6 series and instead provide an option to disable the tracknumber and title guessing completely in 2.7. This should satisfy both the complaints from PICARD-2170 and keep this functionality available in a useful way.