First thing I did when loading prelease 3 was test the new changes, i put a 1 block layer in front of me and one chest and on the other side a horde of piglins, not matter how many times I opened it or broke it they didn't care unless I was in their line of sight. 

EDIT: After further study I have determined that piglins will get mad when you break a chest out of line of sight however they won't care if you open one, I am attaching a screen recording of my test.

Final Edit: After rereading the pre3 changes I have determined I am just stupid and thought i read that they will get mad if they hear you open a chest however it was only breaking desired blocks not opening them, however that would be a welcome change to make it harder to steal from them.