Pasting text with endnote(s) does not show a message. You instead get that message the NEXT time you paste an object, even if that object is not a text box containing endnote(s).

There is also a grammar error in the message, where the word "and" should be ", which" — and there is no period at the end of the sentence.

This has been in many versions of InDesign. I am using 17.1 now.

Reproduce:
- Copy text with endnote(s) to the clipboard
- Paste text into a new thread
- Text pastes properly; a new page is added for the endnote(s) (I am not commenting on THAT behavior)
- No message appears
- Copy a text box or other object(s)
- Paste
- Message appears: The text that you have pasted has endnotes and have been placed at the end of this story