Links to new pages created from the Wysiwyg editor create only terminal pages

Steps to reproduce:

• Edit a page in wysiwyg mode
• Use the Link Wizard to add a link to a new, non existent page 1_LinkToNewPage.png
• Type a page name, like "Process four" (like in 2_TypePageName.png), type the rest of the configuration of the link (label, etc).
• Save the document with the link to the new page in it 3_ResultLinkToNewPage.png
• Click on the link to the new page and create this new page (choose template blank page, type something in the editor and save)

Actual result:

• The created page is a terminal page, it cannot have children See 4_ProcessFourIsTerminal.png .
• Clicking the add button on this page will create a sister page of this page, not a child page

Expected result:

• The newly created Process four page should be a non-terminal page, we should be able to create children for it

Note that this issue also reproduces if on step 2 we use the tree UI to create a link to a new page (as in 1_1_LinkToNewPageTree.png).