As a rule to do this I leave a hint to myself in the fieldname eg; newname-list and with the relink plugin installed add the new fieldname newname-list to those it keeps up to date, then the list field is maintained if one of the titles within it are renamed.
You may be interested in How to modify tag-picker macro to store values in a different list and myu own effort for a tiddler picker Wikitext and widget MACRO solution for tiddler-picker - HELPed myself - #7 by TW_Tones and specifically https://sandbox-by-tones.tiddlyhost.com/ more of a work in progress and scratch area than published.
- I am tidying it up now.