They only give second chance chests to certain bosses for two reasons.
Ratbeard Generally speaking, two things have to be true before we'll consider adding a Second Chance chest:
1) Is the boss in question at the end of a really long instance?
2) Does the boss in question have unique loot?
I don't know about the Snake Pit, but the Mooshu guardian bosses and the Ulysses palace dungeon doesn't take that long to complete. In fact, you don't have to face a mob fight in the Mooshu guardian dungeons.
Bottom line, I doubt these suggestions will go through.