Why centos-webpanel.com use Cpanel instead of CWP

I was trying to confirm a security problem on email server from CWP and found that the website of CWP use cpanel instead of CWP.

It's only for me that this seems really odd?

There are any reason for that?

probably you mean on the old site, however, cwp started as cpanel expansion module so it still has some old services running on one old cpanel server.
Also, it can be used for testing and comparing.

I don't know what is the old website but the current one https://centos-webpanel.com/cpanel is  clearly  on a cpanel.

It's strange to create a webpanel as alternative to cpanel and then use cpanel to host the main website of the project.