If it's not sustainable? Yes. They shouldn't have hired them in the first place then. Such a major round of firing (the second one in only a few months) shows a completely failing leadership.
I'm glad in Europe companies are much more conservative with hiring and firing. Because it's much harder to let employees go and there's strings attached.
Don't forget when you fire an employee you're giving them a lot of stress about their livelihood, you're externalising a lot to society. Internalise the profits, externalise the problems. Typical.
I'm so glad I don't live in the US and that things don't work like that here.