Guardinals

In thread number 5 you said that guardinals promote over time. In the thread "Do Celestials get promoted" you said they (and curiously also eladrin) don't get promoted. Now which is true?
No book makes any statement on the matter except the exceedingly terrible Warriors of Heaven. The answer from Glyphstone's thread was from that and from the lack of any other answer available in a book to note things one way or another. Neither eladrins nor guardinals get much fleshing out anywhere, sadly.

Within the context of this thread, Warriors of Heaven is specifically not an acceptable source and its information is not applicable. That's my final word on the subject.