I do not know and have no way of knowing if "ph shock", or "TDS shock" or "temperature shock" really occur. I do know that quite a number of fishes are lost during their settling-in period.
What I can see is that the fishes do get traumatized when they are netted - their colours fade and do not return for quite some time, also they have a tendency to hide when released and their movements are not free. Further observation is that in their new tank they are subjected to curiosity of the other inhabitants some of whom even peck at the new-comers.
If the new fishes get a chance of gently being introduced to their new environment and being given some time to come out of their netting trauma in the isolation of the bucket wouldn't it be better for them, and easier for them to settle into their new tank? I would continue with my transfer bucket method described couple of posts here above - I feel I owe my pets that much.
You are catching on! Nice to see that you are aware and observant! It seems most people don't take note of all the stressors applied to fish.
Whether pH shock, TDS shock, temp shock, etc., everything boils down to one thing, that being stress. It can be a little bit of a multitude of different stress factors that can ultimately lead to a fish dying, which is witnessed in fish dying during acclimation or even transport.
So just think of the travels and everything the fish goes through to get to your home and just look at all the stress building up on the fish. Even things such as lighting, people presence, vibrations, o2 levels, so so many things that are indeed stressors to the fish. And the things you mentioned (netting fish and the chase, fish getting to a new environment, other fish staring at it or messing with it while it is in a vulnerable state/stressed, etc). There is only so much stress a fish can take, everything adds up. Of course toxic levels in their water is a major stressor as well. Best thing to do for best success is to minimize as many stressors as possible. Of course fish aren't THAT fragile, but they surely could use some help.
Temp. shock is definitely a real thing, but depends on the how healthy the fish is, stress free even. Again a weakened/stressed fish can't take as much "shock" (stress) as a fish who is healthier/already acclimated/settled in. Although healthy fish are definitely more tolerant of instant temp changes then they are given credit for.
I haven't looked into pH shock or TDS shock, so I can't say for sure, but sounds like they can be factors just as well.
Just had to commend you for taking observations and thinking proactively.
But as for your current plan for acclimating, it can be revised and done in better ways. The desensitizing to new environment isn't really necessary unless you have aggressive fish (cichlid owners have used "kritter cages" so the new fish is safe from attacks from other fish, but still can be seen so they can become acquainted and the new fish can "check out" it's new environment). Just gentle acclimation to water params is enough, but more shaded hiding spots are definitely a plus (or turn off lights). I am sure you can figure things out.