Those plasmoids are intended to replace the old systemmonitor plasmoids
They are based upon the new ksysguard daemon: see D28333 and D28141
It has pluggable presets and sensor "faces" which are available from the KDE store
Every preset is available as a separate plasmoid.
By default are installed ones to replace
roughly one by one the existing systemmonitor plasmoids so systems that use it
will get the new ones in the updates