Yes, but Zavvi aren't producing steelbooks for Captain America and Thor just because people missed out, but because people who missed out, people who collect steelbooks, people who collect variants and people who collect Marvel titles will buy it.
They're a business. They don't care if it upsets those who bought the original and why should they? I bought the originals, I opened them and watch them. I don't care if these new ones are identical or not, it makes no difference to me. I have what I have. It's not for resale, I don't even display them. They're just for my own enjoyment.
It's like cars. BMW makes a 3 series and it sells. They do them in different colours and they sell. A couple of years later, they release a new style 3 series. It's essentially the same as the last one, styled a bit different, and they sell too. BMW doesn't owe me anything. I paid my money and I took my chance. Yes, the new one looks a bit nicer but I'm not going to rush out and get it (not that I could afford to anyway).