Yes, just like any lumber, you should ideally always sticker your pressure-treated lumber and let it sit for a couple weeks before using it to let it dry out and acclimate to your environment.
Wood moves as it absorbs or releases moisture, even the moisture injected into it during the pressure-treating process. All you need to do for proof is to look at the picnic tables sitting outside your local home improvement center about halfway through the summer. After they are assembled and set outside for display, they start to acclimate and after they've been outside for a while, one leg is often several inches off the ground.
You also mentioned in a comment that you have a SawStop table saw. Typically pressure-treated lumber will not trip the brake, but there's an easy way to test whether any material is conductive enough to be detected as flesh contact.
- Set up your saw for an extremely safe type of cut--for example, using a crosscut sled to remove a few inches of material from the end of a board
- Start the saw in bypass mode (you should check your saw's manual, but the steps are the same as the ones I've copied below from the Contractor model's Quick Start Guide).
WARNING: Only use Bypass Mode to cut conductive material or to test material conductivity. There is no protection in Bypass Mode.
- Flip the main power switch up to turn on power.
- Wait until the green light is on steady and the red light is off.
- Turn the bypass key clockwise and hold.
- Hold the bypass key turned for 2 seconds, pull out the Start/Stop Paddle, and hold the key 2 more seconds.
- Release the key. The green light blinks slowly and the red light is off when in Bypass Mode.
- Push the Start/Stop Paddle in to stop the blade. The saw exits Bypass Mode
after the blade has come to a complete stop.
- Very carefully make several test cuts.
- Before turning off the blade by pushing in the red Start/Stop paddle, check the red light.
- If the red light is blinking fast, the material is conductive and would have triggered the brake.
- If the red light is off, the material is non-conductive and would not have triggered the brake.
Last summer I performed this check on a pressure-treated 2x4 and was able to safely rip a bevel across the entire length to make a piece of window trim for the exterior my house.