The word "drop"

It strikes me as a fairly recent phenomenon that the word "drop" has acquired a meaning which is almost the opposite of what the word normally means.

For example, I recently read a headline online about a major retailer who just "dropped" its big Fourth of July sales. To me, that means that they are cancelling the sales, but the intended meaning was that they have announced the sales and will go ahead with them.

This word confuses me a lot now. I am never sure how formally or informally the tone is supposed to be, so I am not sure if someone is saying one thing or the opposite!

OK, end of "old guy" rant!