I will submit my PhD thesis for review next month. Do I already include Acknowledgements within this version?
This seems a bit wrong to me since it indicates that I expect that I will definitely receive a PhD even though I have not had my defense yet (anything might theoretically happen...).
There is a similar question (Should supervisors read acknowledgments before the printed version of the thesis?) but I need a more PhD related answer. I mean, all members of my dissertation committee will read the Acknowledgements before I actually published my revised thesis.
Yes, include them. I don't find it arrogant at all that you believe at review time that you will do well and pass even if there are changes to be made. Lots of people are asked for some minor revisions, and your committee members know that. Your supervisor should not let you submit it for review if they don't believe that your work is sufficient to pass review. They should also not allow you to have a defense or viva or whatever it's called in your locale unless they think you will pass. It's fine, but you could also ask your supervisor their opinion.
Believing in your work is OK. How would you ever publish a journal or conference paper after your PhD if you didn't think it would be accepted? You have to start believing in your own work, on your own, at some point soon. That's part of being an independent researcher which is what your near future is about.