Sandbox changes are focusing on the symptom, not the problem.
I think the rework of the ammo is fixing a symptom of the problem instead of the cause of the problem. What Wargaming is doing by changing special/gold ammo is the equivalent of shoving gauze up the nose of someone who is bleeding and dying out from a hemorrhagic disease.
The issue isn't gold/premium/special rounds. The issue is map design, lack of real weak spots on many tanks, and RNG. Wargaming loves corridor maps that make players fight frontally. How many of their maps are two corridors that promote frontal engagements with an area in between that is a death zone for most tanks? How many tanks/TDs have little to no frontal weak spots? How many of them have weak spots that can be easily penetrated by standard ammo of the lower tier tanks they face? How many times in a row have you fully aimed a shot at the weak spot of a stationary tank and have RNG send the shot too low or too high or too far too the side several times in a row? How many times in a row have you fully aimed a shot at the weak spot of a stationary tank and have a low penetration RNG roll that caused the shot to bounce off a weak spot. Before attempting any changes to ammo, they need to fix the other areas first. Wargaming is fixing the symptom, not the problem.
Personally, I think Wargaming should change RNG to +/- 15% for damage and penetration. WoT Blitz has 15% RNG if I remember correctly from playing it before. In addition to that, many maps need some rework to allow more flanking opportunities. With the current design of most maps your flanking choices are to go to another corridor to fight tanks frontally just as you were before, or crossing into an open area where most players get spotted easily and die quickly. Tanks also need weak spots that can actually be hit and penetrated by lower tier tanks.
I'm not saying every tank needs large weak spots that every tank 2 tiers lower can easily hit and pen at 200+ meters. However, the weak spots of many higher tier tanks are small enough that when you are less than 100 meters away, your aim circle is 2 to 4 times the area of the weak spot. Regularly having fully aimed shots at a tank's weak spots miss at under 100 meters because the weak spots are so small they can't easily be hit is a problem. Skill in learning weak spots and aiming for them is negated by RNG in many circumstances. It also works the other way. There are tanks that have been relegated to being useless after nerfs or changes because their weak spots are so large and easy to hit. The T110E5 is one example of this.
Before touching gold/special ammo, Wargaming should look at the other major issues with the game with map design, armor, and RNG.
The changes on sandbox are an over complicated way of fixing a symptom of the real problems.