Hey, I agree with you about the lack of ghost flavor in CAP (including my own) but before the rage descends you might want to take out that part about chandelure being fire primary :P because knowing the internet they will focus on that instead of what you're actually saying.
When an ASB Pokémon gains a +speed nature, it gains a boost to accuracy as well. This is determined by your speed. Trapinch goes up to 12 Speed. So, we square that to get 144. We then divide by the divisor (The divisors change as you evolve, and are listed in the post I linked to in the reg tower). Since Trapinch is the first of a 3 stage evolution family, it gains accuracy equal to 144/290, which is just below a half. Since your Accuracy boost is below 5%, it is automatically raised to 5%. This means that all your attacks gain a flat boost of 5% to their accuracy. So Fissure goes from 30% Accurate to 35% accurate, and Sand Tomb goes from 85% Accuracy to 90% Accuracy. This will change when you improve, and gives pokémon with +speed natures a useful boost.