Here is a patch which converts "Contributed by" notes in whatsnews to most prevalent style. This means: * Previous sentence ends by a period and the "Contributed" is titled. * The note ends by a period and it is placed before closing parent. * The note is separated from previous sentence by two spaces or newline (as any sentences). Overwhelming majority of "Contributed by" notes are written in this style (except of unfinished 3.5 whatsnews).
I agree with making a complete and separate sentence. There are 3 variations. -- Add parenthetical note after last sentence. (Contributed by me.) -- Add note on next line after short line. (Contributed by me. -- Add note after a blank line. (Contributed by me.) -- I guess version 2 will be formatted the same as version 1. In 3.4 What's New I only say one instance of the 3rd, blank line style, for the multi-paragraph Improvements to Codec Handling, which it arguable was appropriate.
Yep, that's exactly the logic I used for "trailing parenthetical sentence" versus "trailing parenthetical paragraph": whether or not what was being referenced was a single paragraph for a block of paragraphs. I went through and made 3.4 consistent, so there should be no changes there. Likewise the editors of earlier whats new should have made those consistent, and it is probably best not to second guess the editor absent a glaring typo. If you want to make 3.5 "currently consistent" by all means do so. However, a final edit pass (or passes) will be needed at release time whatever you do now.
