Interestingly enough, the earlier history on this topic stated that it was due to the Korean type set, leading Koreans to come up with the abbreviation on their own as a form of short hand. When this history changed to it's current form, I can not say. I can only attest to this being accepted fact at that time.

https://www.slanglang.net/slang/internet-culture/top-kek/

Kek originates from Blizzard’s Starcraft, where Korean characters weren’t supported and when a Korean player wrote “hahaha” it displayed “kekeke” with latin characters.

Blizzard kept the joke going in World of Warcraft, where Horde players writing LOL was seen as KEK by Alliance players.

Top kek was born nearly 10 years to the birth of World of Warcraft, when 4chan users discovered the Turkish cake; Topkek.