I did search and according to this post (MCPE-10985) it says "resolved" but that was months ago so im not sure if im reading it correctly but slimes still do not spawn in swamps at night. I have been to 3 swamps in my normal survival map and no slimes have spawned. Sorry if i did something wrong but when it says "resolved" and there is still an issue i thought better safe than sorry and report it.