I don't understand why people post a link to a website that only redirects you to a different website, why not post the direct link instead?
Gnome
The GNOME Project is a free and open source desktop and computing platform for open platforms like Linux that strives to be an easy and elegant way to use your computer. GNOME software is developed openly and ethically by both individual contributors and corporate partners, and is distributed under the GNU General Public License.
I think that's just how Mastodon handles the federation with Lemmy, there's not much users can do about it.
What do you will need new color states in GTK for? I'm not sure but I hope I will get better looking fonts into my editor because of this change. But not sure and this is only guessing
HDR and 10+ bit displays
You're unlikely to see any improvements if you don't use either of these, but it's a welcome change for graphic artists and people using high bit displays.