But that's off-topic to some extent; I scanned through this page looking for some good news for developers. Topping my list is support for SVG assets. NOPE. WTF? Android has had this how long? Apple's "@2x", "@3X" bitmaps were amateur-hour to begin with, but a decade later? No vector support?
Come on.
And still no user-definable color schemes. Windows (and Unix GUIs, for that matter) had them for decades, while Apple forced its late-'80s inverse scheme on every user that whole time. The hard-coded "dark" theme is a half-baked, belated admission that staring into a glaring light bulb with black text on its surface all day may not be the best way to work.
This would also have been a great time to abandon the single menu bar, but nope; that poor decision continues to plague Mac users. Really, this should have been canned in the transition to OS X, but now there's even less of an excuse.
I'm sure there will be some good changes, but from this list I'm not encouraged. Getting rid of the distinction between toolbar and app content... WHY? The "flat UI" experiment was a failure. Let's continue to take tasteful steps back toward GUIs that communicate in universal visual terms whenever possible.