What is happening with these solar particles detected near the Sun that is so newsworthy?
If I understand your question correctly, it is about EPI-Lo which a part of the Integrated Science Investigation of the Sun (ISʘIS) . The picture is also taken from there:

EPI-Lo stands for Energetic Particle Instrument-Low energy which indeed sounds confusing at first sight. The essential definition can be found in the instrument paper:

EPI-Lo measures ions and ion composition from ∼20 keV/nucleon–15 MeV total energy and electrons from ∼25–1000 keV. EPI-Hi measures ions from ∼1–200 MeV/nucleon and electrons from ∼0.5–6 MeV.

The paper also addresses the scientific background of the measurements of SEPs, which are defined to have the following energy range:

They consist of protons, electrons and HZE ions with energy ranging from a few tens of keV to many GeV.

In short: The EPI-Lo measures the lower part of the SEP events.
Concerning the newsworthyness, I can only guess. Why SEPs are worth studying is nicely stated at Wikipedia:

They are of particular interest and importance because they can endanger life in outer space (especially particles above 40 MeV).
Solar energetic particles can originate either from a solar-flare site or by shock waves associated with coronal mass ejections (CMEs). However, only about 1% of CMEs produce strong SEP events.

I hope that my remarks answer (at least partially) your questions.