It is intended that HL will contain Soldiers of the Negus, which was originally a fan type desktop publication (unmounted counters) addition ('94) later taken up by CH ('96), who did it with real counters. From what I gathered the CH version was a once off licence for SotN, the original authors retained the rights. MMP have obviously got the originators permission (at least) to do a version.
SotN, as you correctly surmised, is about the Italian invasion of Ethiopia. The CH version had 200 x 1/2" counters, mainly unique mainly Ethiopian infantry/SW (80%) with some Italian colonial infantry (20%). There were two of what should have been 5/8" done as 1/2" in the CH edition simply because of counter sheet limits.
What numbers of counters will be in the MMP version, I haven't a clue. Being part of a bigger package, MMP won't be quite so constrained, but I don't expect multiple SotN counter sheets.
From BGG:
https://boardgamegeek.com/image/259990/soldiers-negus