Follow-up and Swan song

Follow-up noun - A piece of work that exploits or builds on earlier work.

Swan song and follow-up are semantically related. in afterword topic. In some cases you can use "Swan song" instead a noun phrase "Follow-up".

Swan song noun - A final performance or effort (especially before retirement).

Follow-up and swan song are semantically related. Sometimes you can use "Follow-up" instead a noun phrase "Swan song".