In 2018, a card featuring a pair of legendary minotaurs became the subject of one of the biggest Magic: The Gathering controversies in years.

Back in 1994, Magic had faced heat for making one of their cards that year, Nalathni Dragon, only available through going to Dragon Con. After major fan backlash, Wizards of the Coast decided to have another way to release it to the general public and made it a freebie through buying a magazine and other methods.

After that whole debacle, the company vowed to never have such an exclusive release again and have all cards available to the general public one way or another. And that's exactly what they did. For the next 24 years, that is.

Jump forward to 2018. the set Dominaria is coming out and, once again, they had their buy-a-box promo. Basically, as a promo for releasing each set, players who get a booster box can get a free promotional card. It's usually a foil version of a card found within that set, but with alternate art. These promos tend to be somewhat popular on average.

So, with Dominaria, they continued the tradition by offering Firesong and Sunspeaker as the set's buy-a-box promo. This time around, though, the card wouldn't be found within the set. Instead, it was a card that was exclusive only as a promo.

It's the Nalathni Dragon thing all over again.

While not every players cup of tea, the fact that you couldn't get the card out of the booster packs made the fanbase angry. It set off a bit of firestorm in the fanbase.

While Magic did say they heard the fans out, the resulting debacle it caused, as well as it causing more fans to go in on the program and Magic to get a boost in sales, led to them continuing to do the same thing.

For the next several sets, more exclusive cards not found in their respective main sets were released, such as Nexus of Fate in Magic 2019 (a card which would see the ban hammer in three formats), Kenrith, The Returned King in Throne of Eldraine, and Tezzeret, Master of the Bridge in War of the Spark.

As more cards were released this way, and the fan base grew a just bit more annoyed until finally, by the early 2020s, Mark Rosewater announced that they would be ending the practice. From then on, WotC says cards would either be released in the boosters or just be a special variant once again. 

Since then, the furor has died down. But, considering the backlash, the majority of players are hoping to never again see another Firesong and Sunspeaker thing happen again with MTG.