User blog comment:Lia Schiffer/395: The Burnout Inferno 3/@comment-44061-20100313191650

Seals are never permanent and Aizen seems to presume to much on his ability to counter others powers. Seeing as he also was under the assumption that Wonderweiss could kill Yama and that without his zanpakuto he was no danger. I also dont recall Aizen saying forever. There are various translations but, in translations so far he either just says seal them away or seal them away so they can come out no more. Mangasteam is a bit fast and lose with translations. In any case WW is dead and Aizen wasn't speaking in long term apparently but rather in the moment. The comment was meant to address the flames that were gonna explode out of WW's body. Its too much to presume the words hold wait to that point when we don't know for sure.