My textbook includes numerous examples of 次第, such as following nouns in which it can be translated as "depending on", or when following the 連用形 of verbs in which it can be translated as "as soon as", but it includes another set of examples in which it follows the 連体形 of verbs and is followed by the copula です.
The following is one such example:
(I will inform you later of any changes in the time and place of the meeting.)
The only explanation that the book gives for this kind of usage is to gloss the sentence with "知らせるわけです".
Looking at these such examples, it seems to me that this type of 次第です may be a type of polite language. Is this correct? What are the nuances of its usage?