Edit: Daily endeavors did indeed start on June 17, as expected.
On or around June 17, 2021, ESO plans to introduce a new currency (Seals of Endeavor) and ways of earning it (Endeavors). The purposes of this thread are to:
• Outline the basics of the new system.
• Collect tips, bugs, observations and so on about particular endeavors.
• Offer a convenient place to link other guides to the endeavor system.
Its initial posts rely heavily upon observations in
a similar thread that was based on PTS experiences.
The basics of what is and isn’t known about seals include:
• Much like gems, seals will be used to buy items found in whatever are the currently available “seasonal” crown crates.
• Gems and seals will be separate from and not convertible into each other.
• Until the system goes live, we will have no clues as to what items’ prices in seals will be. (On the PTS everything cost 1 seal, much as is the custom for PTS crown store items.)
Based on the PTS and other considerations, it seems likely that the list of items available for seals will basically be:
• Anything can also be bought for gems, ...
• … EXCEPT items that duplicate things that could be gotten in other ways in-game (e.g. experience scrolls or other consumables).
I.e., the new system seems designed to ensure that everything sold in crown crates is more-or-less available in-game as well.