This has most likely been done due to the presence of broken links on the page (due to either link rot or outright linking to nonexistent pages), as well as the inactivity of said user (defined as no edits since August 1, 2018
, although exceptions can sometimes be made).
If you are the owner of this page, then you can revert this blanking by going into this page's History tab
, and then reverting the blanking edit(s).
However, keep in mind that it is your
responsibility to make sure links continue to point to the pages they are intended to.