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I personally doubt that Angela will make a return. She was a character that was created before Insomniac ever cared about Lombaxes, and she never once expressed any emotions regarding her and Ratchet's missing race. This would be because, as far as Insomniac were concerned, the Lombaxes were not written in as in any danger back then.
Insomniac has expressed before that they grew tired of the questions regarding Angela long long ago. They even said that they added the radio broadcast in ACiT as a sort of message to us that she is a Lombax and she isn't coming back. But despite what they suggested in the forums back then, the radio broadcast itself has failed to conclude the idea that she won't be returning, as many took it as a message that she is still out there somewhere.
TJ has said that he knows what Ratchet's name is, and he knows what he would do with the story if they came around to another major release for after the Future series. If they were to make another game after ITN I bet they would use TJ's plan, and I don't think it is likely that Angela is in it.
Either way, Insomniac Games are not allowed to take any ideas from their fans. Not for weapons (unless in a contest), and not for story plot. So I am afraid you idea will not move beyond the world of fan-fiction.