I absolutely agree. I read this article, I was hesitant about using my private memo key, but I was in a hurry and didn't check other information. I got some weird thought that bittrex is about to send some encrypted memo and that's why it needs prev key (that's total nonsense).

And the result is:

Thanks to @noblebot for its automated checks and for notifying me. Fortunatelly, I don't have any secret memos that others could now read, but still, this article in its current state NEEDS CORRECTION or DELETION or at least enough downvotes so it's ghosted.

@cryptotrends if you're online, please correct it.

"Memo" field is just an opaque text that will be sent back along with the transfer.
Nothing more.