My books go both ways . . . . umm . . . not like that. I mean they get smaller and bigger.
My first edit, I tend to go through and make sure I have descriptions of the way things look, smell, sound, taste and feel. That usually adds another 2000 or so words per 100,000.
Then I remove the word 'that' which lowers the count by a thousand.
If something needs to be fleshed out or added, I put on more words.
Then I go through and get rid of redundancies. I have a habit of saying the same thing in two or three words.
My first book started out as 104,000 words before edits. My wife told me to add a chapter to develop the characters a little more which added 3000 words. the final count was 107,000. Basically, if I hadn't added that chapter, the word count would have remained the same.