Considering that when you delete a page your in effect telling the system you don’t care about that keyword it should give you the option to remove links else the page will keep returning.
I’n my use case I usually merge the page to something else that’s more fitting to get rid of a keyword, but if you really do need to get rid of a word you could use something like sed or vscode to do a find replace for [[pagename]] and replace with pagename.
Example on how I use sed to remove example page links and replace with just the text, I run this in pages and journals directory.
sed -i 's/\[\[example page\]\]/example page/g' *