There is no definition of WSG in the English Dictionary, whether you're wondering about the Oxford, Cambridge or any other edition. As you know, it’s a term used to abbreviate a common American greeting and it’s not even that popular for it to deserve a place in the dictionary (as of now).
However, popular Internet terms have had the honor of being entered into the official English Dictionary, in the past.
Take the slang word Hangry, for instance, which is the combination of the words Hungry and Angry. It is used to convey anger that’s usually caused by hunger.
It’s present in the dictionary along with the term Bougie, which is just short for bourgeois.
Guac is also a word present in the dictionary and as you may have guessed, it’s short for Guacamole.
Another popular abbreviation from the Internet that has made it into the dictionary is TL;DR.
It’s short for Too Long; Didn’t Read. It’s used for summarizing long posts into one short sentence for those who don’t feel like reading the whole thing.
As you can see, many words very common in Internet lingo do find their way into widely accepted dictionaries.
While WSG doesn’t have that kind of popularity right now, who knows what the future has in store for it.
It might just become as popular as Hangry and get entered into the Oxford English Dictionary.