The conclusion in a dissertation acknowledgement serves only the purpose of winding up the note. But you can use a bit of your creative writing skills and make it an impressively concluded acknowledgement.
Writing a dissertation acknowledgement is all about personal satisfaction. It will not be graded or used as a criterion for grading.
The fact that dissertation acknowledgement is the only informal part of a set of formal documents makes it difficult to decide what is suitable for it and what is not.
You must check your dissertation guidelines to see if there are any instructions regarding the dissertation acknowledgement. The word limit matters a lot while determining the structure.
The length of the dissertation acknowledgement will depend up on the number of people you wish to acknowledge. But it must not be longer than one page.
Dissertation acknowledgement is a personal note. What counts more than anything is the personal satisfaction you get to see the names of those who helped you in your official document.