References must be cited vs. need not be cited In reviewing publishing guidelines prior to submission to a journal, it is listed that "References need not be cited in text." This is also listed in the style guide for the associated professional society. 

While simultaneously, the Elsevier guide for authors states "Please ensure that every reference cited in the text is also present in the reference list (and vice versa)." Likewise, a previous question asked on this board received almost unilateral support for  the one citation, one reference style.

My question is what purposes would there be for allowing uncited references?

Or alternatively, could someone clarify what is meant by "References need not be cited in text."

Edit to clarify: My interpretation of "References need not be cited in text" is that it is allowable to include a reference in the reference section of a manuscript without citing this reference in the text of the same manuscript.
This sentence is present on page 5 in the IEEE guide at:

https://www.ieee.org/content/dam/ieee-org/ieee/web/org/conferences/style_references_manual.pdf

The guide gives an explanation to it as follows:

References in Text: References need not be cited in the text. When they are, they appear on the line, in square brackets, inside the punctuation. Grammatically, they may be treated as if they were footnote numbers, e.g., as shown by Brown [4], [5]; as mentioned earlier [2], [4]–[7 ], [9]; Smith [4] and Brown and Jones [5]; Wood et al.[7]

This clearly means that numbers rather than the author name (s) are preferred to be used in the text. When author names are used, the guide gives some examples on how to cite them.