Not sure that makes any sense in terms of trigonometry and physics. So you're saying that if the basket was up at 15 feet it would be easier to arc the ball over a tall player than at its current height? The player's ability to judge the proper arc will lessen the further above the player's shot release height the rim is, and that height is generally anywhere from 6.5 to 9.5 feet, but the ball must still go upward over fingertips that are mostly below the 9.5 feet. There will be a slight adjustment to the arc from 10 to 9.5 feet, but that is not made any more difficult by a tall player. If the shooter makes a kind of line drive flick shot near the rim, it's possible that a close defender could block it, but that is the case now and it is always just a matter of a player learning to put the proper arc on the shot, which would be a negligible difference for 9.5 feet.
Now if you're saying that a Griner sized player could extend up over 9.5 feet and impede a two foot jumper, that is true, but it also happens now and a rim at 9.5 feet she will get more goal tending calls, which may crimp her style a bit.
And it will not necessarily be the tall players that will dunk some. It will be coordinated players who can jump, and they may just be 6 feet tall.
I'd wager that if players generally had to hit a 9.5 basket, the arc would tend to be lower and easier for even the less tall players with jumping ability to block. The higher the arc, normally less accurate at some point. Very few players put that big an arc on the ball. I think players like Stewart would have a field day blocking shots on a 9'6" hoop and the awful women's refs would be screwing up goal tending calls all over the place to add to their repertoire of bad calls. Maybe with time players would adjust the arc to compensate for the need to get the ball over the better leaping/taller player .
Obviously somewhat shorter players will be able to dunk on a 6 inch lower basket. But when you consider that most of the taller and athletic players either can't or just don't dunk very often, I'm not so sure you'd be seeing a lot of over the rim play by six footers. Dunking requires fairly big hands and not many women can elevate to do a 2 handed dunk.
If you're shooting at a target 12 feet off the floor, the need to elevate the shot just to reach the basket will put the ball beyond the reach of just about any defending woman on the planet and most men as well unless they are right on top of you or you are very close to the hoop, but the shooting percentages would likely drop.
I also think that if the men's game ever raised the rim, the big men might dominate even more. I think outside shooting would be less accurate. You'd never see a six footer dunk and even the regular lay up would not be so automatic.
That being said, however, one of my UConn days memories relates to a classmate of mine and maybe the best pure shooter in school history, Wes Bialosuknia. Not sure if they still have this, but there was a big charity fund raising week that included various games of skill at a midway in the old Fieldhouse. This one year they had a female student sitting above a pool on a dunking stool under an 11 foot basket. You had 3 chances to make 2 foul shots in which case the girl would be drenched. Nobody could do it during the several minutes I was watching. Then Wes shows up, one of the best FF shooters in college ball. Calmly swishes the first two and into the drink for the girl. He adjusted pretty well.
