I think lack of shade (and they used to have a lack of seating but that's slowly improving over time) is definitely intentional. Maybe trees and greenery are also "easy" things to cut from the budget? I get wanting that perfect picture or instagram shot, but they could really have been a lot more clever with this 'backyard' theme. I also just don't think they quite get the demand WDW has. You can't put in a land with one quick service that has two registers, for example, and no indoor shop. I mean, even Disneyland, in beautiful Sunny California, gives their guests shade. Tables at food and wine have umbrellas, stages have shade structures (not at the moment though) ... I mean, they couldn't even put up a shade structure for the trams! I know it's petty but come on, it's not hard. Go out of the way just a little bit for your guests even if you think it's not "worth it". Sure, you're not likely waiting long for a tram, but if the idea is to improve the look and make guests more comfortable ... at least the new area looks better so there's that ...
Lots of Galaxy's Edge feels barren too (while also having lush areas, but the walkways are free and clear and full in the sun, minus the marketplace, which also seems open from above in spots ... Should be fun in 103 degrees in August.
I know folks give Animal Kingdom heck for being a sweat box because of all of the trees, but I'll take lush forests anyday ...
Anyway ... trees are NOT a bad thing. The new hub in MK would look ten times better with some larger trees. But heaven forbid we block a view of the castle from way down by the train station.