For PoE 2, specifically.

I'm considering a purchase, but the listing seemed unclear as to whether all the DLCs would be included.

Any guidance is appreciated.

Thanks.

Yes, although you'd need to add the free DLC. For more information see this thread;

https://www.gog.com/forum/pillars_of_eternity_series/what_version_of_the_pillars_of_eternity_2_includes_everything_developer_using_random_words_confuse/post2

Seems the Deadfire soundtrack is not included though.

It is. It's part of Explorer Pack that's included in the edition.

I don't have it on GOG, but it does say Explorer Pack included on GOG's page.

"Original Soundtrack: The soundtrack to Pillars of Eternity II: Deadfire by Justin Bell, featuring all-new tracks inspired by the peoples and factions of the Deadfire Archipelago."

I can confirm that the Obsidian Edition includes the soundtrack in both MP3 and FLAC format.