Our Office 2019 fixlets should work for volume licensed versions as well.
From what I understand, Office 2019 is only availabe with the click 2 run technology. This is different from Office2013 / Office 2016 where msi-based installers were available through MS VLSC.
You won’t see two separate sets of updates as you do for Office 2016 (1 set for msi based installs & 1 set for click-2-run based installs).
Are the current Office 2019 fixlets not relevant on your endpoints that have Office 2019 installed?