There are four ProQuest sections that deal with rights and access:
Select Traditional Publishing. You do not need to select the fee-based Open Access Service. Open Access is provided for free through the Washington University repository.
If you choose to delay the release of your work, access to the full text of your work will be delayed for the period of time that you specify. The citation and abstract of your work will be available. The Libraries honor the embargo term selected through ProQuest up to 3 years based on library policy (Refer to the Embargoes section).
Embargoes expire automatically. You may extend or cancel it, but once your dissertation is sent to the Libraries, you will need to contact Proquest and firstname.lastname@example.org to make changes. One renewal for up to 3 years is allowed.
Reasons to request an embargo might include the author is pursuing a patent for the work; the research sponsor requires a specified embargo period; the submission includes sensitive or proprietary content, such as work conducted with a corporate partner or a risk of research participants’ identity exposure.
If you select "I do not want my work to be discoverable in Proquest through Google Scholar and other major search engines," Proquest will not make your work available for indexing until your embargo end date.
The Libraries cannot prevent indexing of its repository site but will honor your embargo date.
You do not need to file for copyright (or ask Proquest to file on your behalf) in order to include a copyright page in your manuscript.
Copyright Questions: WULIB_CopyrightHelp@wumail.wustl.edu