Reddit sleuths have discovered parts of The Division 2 regarding its end game features, eight player raids and signature weapons. These are all either major alterations since Ubisoft's first entry in the series or completely new features.
According to The Division 2's gameplay walkthrough trailer, the clan these four agents belong to is Elite Task Force [ETF], but I will call them Cringey Voiceover Squad [CVS] for clarity purposes. So there is one new thing, as The Division didn't have clans.
The clan window is seen at 02:56 in the video, just before the agent enters the inventory screen. Inventory also offers a glimpse at many new features The Division 2 will have. For example, there is now armour stat on the left, an armour plate will apparently be used for the actual armour stat and it can be seen on the right in this picture. The original poster of the picture, u/ntgoten didn't realise this at first and subsequently marked it as a "gravestone".
Other changes include a lower inventory capacity of 30 items that can be carried and 30 slots that seem to be reserved for various caches. There are also four slots with a symbol that resembles the Dark Zone meaning it will make a return in The Division 2 or at least that The Division 2 will have an equivalent of the Dark Zone, marking the first target for end game content.
Meanwhile, u/phoenixeo has found a way to enter the unfinished parts of The Division 2 website, showing the three different specialisations - Survivalist, Demolitionist and Sharpshooter. The unfinished site also mentions "new co-op activities" that will "offer some of the greatest challenges the Division has faced yet" which probably means the eight player raids that were found by u/Primes---.
There is currently no more info on the raids but it's possible these hidden parts of the website might come online as Ubisoft and Massive Entertainment reveal more about The Division 2 a little further into E3.