Sounds to me just like a shop who chucks in a preview tape into your bag at the checkout. i.e. not part of the item you actually purchased. Just extra items that are elsewhere on the shop shelf.
The Artist didn’t add these to their release. It is just a modification at the checkout. So I’d say “no”
I just looked at your link and see it is to Bandcamp, and as the item is listed by an “Artist” it seems to be part of the release. So my answer makes less sense and I’ll leave this to a Bandcamp expert.
If this is the only way the album comes, then it looks like it is part of the album. Bit of a mess really (and I’d just ignore Picard and delete it from my copy anyway. Picard is only a guide…)
They are songs from the album combined into a preview track so it is music from the existing album - they are listed as a track of the album in bandcamp, and it is part of the same purchase, but they are not part of the original album.
I would add a disambig to these. There must be some snappy phrase that can be made up to show these (includes preview advert of the thing you just listened to)
I can see that a completest may want to hear these tracks. Just seems odd placement to have it on the end of the Release.
The more I think, the more I realise this is the home for them. It is how this copy was sold.
If it was me, I’d be manually hacking my tags on these albums. Likely chuck all the previews into their own little collection folder instead. I guess it is like buying a DVD of a film and they include the trailers as extras.