Not only Mia, but Leo, Vanessa, Van, Hance, John, and the other Saints are also very angry at those Traitors who decided to escape in a situation when their teammates needed their help and if they were with them, those fighters could have still struggled. Compared to any of those other fighters, naturally everyone knows the reason why they suddenly get that information. Actually Alex already informs them about this and because of this Leo and the others already know about this thing.
Naturally all of them thought that those people most likely already went inside of the world tower because that was the only safe place right now for those warriors to escape. Only inside of the world tower they will naturally won't be able to face those Monsters and those Monsters will not attack them. But you can say at the same time every fighter really had one question that they wanted to ask those fighters who just betrayed them like this.