I haven't seen this discussed much in the list of things that colleges will need to reassess about their process given their more limited toolkit to achieve diversity, so let's add another: demonstrated interest.
That factor has always been an additional burden on applicants, and it's more burdensome for some applicants than others. First, you have to know whether a school cares about demonstrated interest or not. Not all schools do. (See: UVA vs. Northwestern, for example.)
So applicants have to know even to add that to the list of things they have to forensically investigate and track. Some schools do a good job publicizing their policies around demonstrated interest, but most don't.
I've had to send kids to the Common Data Set to check whether demonstrated interest matters for a school or not. Are applicants supposed to intuit that on their own? That's nutty.
So we're already assuming that an applicant knows (1) that they need to investigate demonstrated interest policies and (2) that they know where to find the information. Those are two bigs ifs, and that know-how information is not evenly distributed.
Someone like me can blog / talk about it until the cows come home - and I do - but given the signal to noise ratio that's out there, it's dumb luck if someone stumbles on a particular blog post or video or what have you. (#2 in Tips and Tricks here.)
So let's assume an applicant knows that a college cares about demonstrated interest. Now they have to figure out how to demonstrate it. Maybe it's in an essay. Maybe it's in an interview. Maybe it's clicking on links in an email sent by the college that spies on you digitally.
Don't even get me started on all the digital surveillance techniques that colleges use to track your movements on the internet, all to gauge your yield prospects. Vendors sell them those products. "Free" 3rd party tools online for applicants sell that data to them. It's gross.
(For the record: at Inline, our software for applicants, we never have and never will. Because gross.)
So now you're trying to write an essay to demonstrate your interest, but maybe your parents didn't go to college and your counselor is overworked and you can't afford to visit the college (= travel budget, and time off from work for the adult accompanying you).
You can mine the college website to try to come up with ways to demonstrate your true love for that college, but at the same time admissions officers don't like regurgitation. So there's an art to using the website to demonstrate interest.
BTW, here's a post on how to conduct your own virtual college tour. And here's one on how to write a Why College X essay.
See the problem with demonstrated interest? That's a lot of inside baseball.
The silver lining to the Supreme Court decision -- yes, I'm grasping here -- is that colleges will have to reevaluate their admissions process soup to nuts and figure out where the leaky bits are.
And they'll have to look at where the frictions are that discourage a lot of people from applying in the first place. Big barriers are amply discussed (early decision, etc). I did a whole talk on what I call micro-barriers. Those add up too. Here's that video if you're interested.