That's a choice they make if they don't want to utilize it. I just don't agree with the "spit in the face" or bad taste as others mentioned. If they ONLY got the 200$ gift card I would agree it's in poor taste. Coupled with everything else, it's fine.
I mean the alternative is that if they want future blizzard game they have to spend money on a company that fired them and blizzard earn money by former employees they fired. Now they get games for free if they want it and blizzard earns no money on their purchases.
Hell, even if they don't want it, since it's a gift card they can give it to someone they know or care about who likes blizzard games and none of them has to give blizzard money.