The Artifact: In the Steam/mobile app version, first-edition packs for Base, Intrigue, Seaside, Prosperity, and Hinterlands can be purchased similar to promo cards, which give the option of using the cards that were removed from their respective expansions instead of or in addition to the current ones.
Content Leak: The second edition of Cornucopia & Guilds was scheduled for release in early March 2024, with previews starting a few days earlier. However, all the cards were leaked when Jay accidentally made the rulebook available on 20 Feb 2024. The digital versions of the expansion were put up early as a result.
As documented by the Dominion Strategy Wiki, there are quite a few individual cards Donald X. doesn't look back upon fondly. Many of these were removed in the second edition.
Donald X. doesn't think very highly of Alchemy, describing it as "easily the worst" expansion and being critical of many of its cards. When asked what a hypothetical second edition of it would look like, he said he'd rather let it go out of print and rescue the good ideas it did have with new cards in other expansions.
/mobile app version, first-edition packs for Base, Intrigue, Seaside, Prosperity, and Hinterlands can be purchased similar to promo cards, which give the option of using the cards that were removed from their respective expansions instead of or in addition to the current ones.