So what? A change in release point does not imply a change in angle. A change in angle relative to WHAT anyway?
There is a huge change in release point from the same bowler bowling at Trent Bridge and at Edgbaston - about 50 miles. Do you think that this also constitutes a change in angle?
Relative to what ? Well , relative to the other release point.
As a batsman you can only adjust your angle in stance so much . As a batsman changes angle of stance ,to accommodate the change in angle of the bowler , the angle of the batsmans stance relative to the angle of the stumps changes too. Ie / a batsman opens his stance to a left arm over bowler.....he is now relatively squarer on to the stumps. Rhe angle of the wooden thing he is trying to protect has changed , it it more exposed or less exposed compared to when he is side on in his stance.
Another thing is the wider on the crease a bowler goes the more a batsman cannot cover the change in angle without dramatically changing their stance , again , you can only do so much of this before you morph into shiv chanderpaul and suddenly need to modify your whole technique to compemsate.
I'll take the wisdom of 100s of thousands of cricketers for 100s of years over your 'revolutionary' point of view.