WordPress PermaLink Structure

Hello. I recently worked on a redesign of an old established site. We made a self hosted wordprerss site.

As this was an established site there were several links pointing to it from other sites and on documentation.

for example: domainname.com/pt
The structure of the site changed now that we are using wordpress.

So the new link to that page is:

domainname.com/something/something/pt

When I type in domainname.com/pt it searches for the pt and actually pulls up the correct page.

Is this a fluke or will this continue with other pages?

like: donainname.com/woop
would recognize:
domainname.com/something/something/woop

and so on?

Is there any documentation that describes this behavior? If it is not a fluke it will be really easy to create redirects by changing the page names rather than actually creating redirects…