Context Marcos, youre smarter than this.
Example: When I was doing my apprenticeship ~20 years ago, we had a supervisor who did a quote. the TL;DR of the quote/estimate sent off was “prepare & paint all external surfaces”
What he didnt do was breakdown which surfaces and, as he had no clue (seriously I could have done his job better, even as an apprentice), completely missed 3 courtyards contained within the perimeter of the building, meaning he under-quoted by a significant margin, all due to the absence of a few key words. Contracts were signed, supervisor got shown the door.
Clarity is essential. No, its not a contract, but clarity is still essential when dealing with clients. The original lacked any form of clarity, thats simply fact. It could have led to people dusting the “free for the event” cards that they owned the originals based on the original article, thats is simply fact and, yes, Blizzard would be 100% responsible for it as they had not (at that time) FULLY disclosed the fact that the cards were only “free for use” during the event.
Its similar to my above analogy as, when I am told that I will get all 23 cards for FREE during the event, without any mention of ONLY for the duration of the event, that implies that I get to keep said cards, even if I cant dust them.
Yes, we can ASSUME that we lose them when the event ends, but without confirmations assumptions makes an (contains a word not allowed, 1st 3 letters) out of u & me.
Clarity. Is. VERY. IMPORTANT! Something which was lacking in the original article.