Hey there,
From the limited info available online (it doesn't appear to have any reviews) it seems the Core PSU's are a replacement for the Focus line. The Focus' were/are excellent PSU's. The Core Gold GM comes with a 7 year warranty, and although that doesn't imply how good the PSU is, you can bet like with a lot of Seasonic PSU's they are made with high quality parts.
From the power standpoint it's absolutely fine. The Rx570 only requires a 450w PSU to work correctly. With the Core, you have a little headroom. This depends on what other hardware you are running though too.