SSA Congestion Count vs Resources all in use

[CarGoSki]

I see two alarms that appear similar and I believe I understand the difference between them. Perhaps someone knows with certainty.

I see 125 instances of preferred edition licenses all in use and 6 instances of voicemail channels all in use.

VM channels all in use corresponds with Resources congestion counter in SSA however there is nothing in SSA that matches 125 events. So I am guessing that Preferred Edition Licenses All In Use simply means that all are in use but there is no congestion.