The High Isle Chapter and Update 8.0.0 have just been released on PTS. They add promotional banners for many new Crown Store items and the next season of Crown Crates called Dark Chivalry.
The collection of items this time is rather robust with most of the regular Crown Store item categories being updated.
There are new non-combat pets and mounts, including Luminous Meridian Charger, Wailing Shackler Wolf and Wealdspirit Bear. These three will likely be the Radiant Apex rewards in the Dark Chivalry Crates. Another interesting mount is the common Quasigriff, which is similar to Dagonic and Aurelic Quasigriffs but it seems that it will be a Crown Store item rather than an event reward.
The new Outfit Styles include the long-awaited Dawn's Avenger Style that was first datamined more than a year ago. The Undaunted Arms Packs in this update are Encratis and Nazaray, themed after the bosses from the Black Drake Villa and Shipwright's Regret dungeons.
The update also adds new Adornments, Emotes, Markings, Costumes, Motifs and Furnishings, including the Deadlands Harvester, a new target dummy. There is one new Hairstyle as well, the Cutting Edge, which might be a good fit for a pirate character.
Finally, there is an unusually large number of Skins and Polymorphs for one update. The Skins are Bargain-Marked Skaafin, Ethertide, Reefdweller and Mossblood Imp Epidermis. Chances are at least one of them will be in the Crates (probably either the Ethertide or Reefdweller, or perhaps both). The Polymorphs are Soulrazer Knight and Winterborn Spriggan. The latter will likely be a Crown Gem exclusive, available along with the Winterborn Wild Hunt Wolf Mount.
You can also check the previous datamine from the Ascending Tide DLC if you missed it as some of the items that were datamined back then haven't been released yet.
If you want to discuss this datamine with other ESO players, you can join the ESO Model Viewer Discord server.
Keep in mind that these pictures were found in the game files and the items pictured are not officially confirmed. As such, they might change significantly on release or might never be released at all.