Spotlight no longer indexes .rtf and .rtfd files. Notes came back. Lists don't match. Stickies still orphaned. -Additional Info
As I have lost confidence in Spotlight I use an additional, third party search application, Houdahspot.
Yea, crazy name but it's an excellent application, far more precise control over search.
A recent upgrade sent me to a blog post I found of interest and adds some further explanation to my original posted questions / comment on Spotlight issues, "Spotlight no longer indexes .rtf and .rtfd files. Notes came back. Lists don't match. Stickies still orphaned." To avoid confusion, I would have just added this to that post but Apple has prevented that.
"Searching Apple Mail Messages" - Houdahspot blog: 2020 12 07
In brief, Apple created something called Core Spotlight and locked third party developers out of some access to the Spotlight index.
My observation: It appears that at some point there was a delay in adding Spotlight's search for Apple Notes, that now appears to be repaired.
The blog calls out some other issues with Core Spotlight and third party developers.
Unfortunately, at this time, I still cannot get Spotlight to cooperate with my finder. When I click "Show in Finder" at the bottom of Spotlight's search list, the list that appears in the finder is highly truncated and does not show a number of items, some are Notes and Mail.