I think most dictionaries absolutely do contain slang. However its important to keep in mind that bilingual dictionaries still have a target audience of one or the other language.
A dictionary with a target of chinese speakers will likely include english slang, but define it with regular chinese. See example below:
Same thing with dictionaries aimed at an english audience, in reverse, like below:
I do not think you will find any term like GOATed in a dictionary, because it is actually not slang, but an acronym. An acronym specific dictionary would have it but that is less likely to be bilingual.
In the same way I think padawan has not crossed the line into true slang, but is just a pop culture reference. I can confidently say if I had never seen starwars I would have no idea or use of that term. If it crosses that line to be used wildly with no concept of starwars attached, it will be true slang. As is, its less likely to make it into anything bilingual considering even most natives need to look it up.
All this happens in chinese too, not just the english side. Someone would want to go online instead of a traditional dictionary to ask about an acronym like kswl or pop culture reference like 葛優癱
Hope this helps, images from two different pleco dictionaries (◐‿◑)
EDIT: for those who cannot see the photos, the first is an entry aimed at chinese of english slang "iffy". it shows the definition "bad" in english slang with chinese definition of 可疑的；有問題的；有點壞的 as well as slang definition of "uncertain" with chinese definition of
未確定的；有變數的. Note how the english slang is defined with normal chinese not slang equivalents.
the second photo is aimed at english speakers and defines the chinese slang
"同志" with the definition "COMMON NAME FOR gay; homosexual" it also gives the regular definition of "comrade".