The timing for Mageia 7, just prior to the recent release of the new AMD Ryzen 3000 series of CPU’s, didn’t play nicely. Namely, there was an issue with the system starting up on these new CPU’s that prevented any type of installation, except for a net install. So, the only solution was to release a new set of installation media, which are available to download here.
It’s very important to note that if you have a working system, there is nothing that you need to address. This release is primarily to fix installation on systems with the above CPU’s.
Update wise, Mageia 7.1 has a fixed version of systemd and all validated bugfix and security updates as of 2019/07/11. The core of the distribution remains untouched from Mageia 7.
You can read the full Mageia 7 release announcement here.