Tasha's Cauldron of Everything hits our Dungeons & Dragons games next week (DMs willing), so Wizards of the Coast is getting everything ready. Most notably, the D&D designers are getting previous books ready to be compatible with the big changes Tasha's will bring.
Not too long ago, Wizards released a Sage Advice document. Sage Advice is like a mix between D&D patch notes and rule clarifications. It answers fan questions about the wording around certain spells or abilities, and also makes changes to those things. The recent Sage Advice saw adjustments made to racial abilities in light of Tasha's reworking of the idea.
Today, Wizards drew our attention to that same Same Advice but with two new additions. The Sword Coast Adventurer's Guide and Eberron: Rising From the Last War books now have sections in the Sage Advice document. A quick glance shows that Sword Coast changes are largely centered around the Bladesinger sublcass, whereas Eberron saw changes to the artificer. Both are due for a printing in Tasha's Cauldron of Everything. It looks as though the changes were made to have both books match the way their content will be shown in Tasha's.
Also of note are a few small lore changes to each book, which might have to do with how Tasha is going to present things in the upcoming book. Tasha has never been to Eberron that we know of, so her section on artificers will have to introduce new lore for the magical scientists.
Tasha's Cauldron of Everything will release in the US on November 17, and In Europe and Asia on December 1.
Source: WotC