The world--and especially the tech world--is such now, that I never know if a word is misspelled or if the spelling is intentional and has a meaning I have not yet learned. Or learnd.
It's generally spelled “whiskey” — with an e — in the United States and Ireland. It's spelled “whisky” — without the e — in Scotland and Canada. Since this article is about Glenfiddich, which is based in Scotland, it makes sense that it's spelled without the e.
The reason for this is purely historical — there's not necessarily a difference in the product. That said, "Scotch" must be produced in Scotland, and hence you'll always see "Scotch whisky" (no e).
It's actually not so cut-and-dry as you might think regarding the USA. Even some bigger brands like Makers Mark call theirs "whisky"
But anecdotally as a Scot, the only people who really get upset about that extra "e" are non-whisky drinking Scottish people :D Those who drink it are, in my experience, generally pretty chilled out and understanding.
Glenfiddich was founded in 1886 in Scotland.