No, that’s the patch level the factory images have set, those are C.073 so definitely too old. We would need the SPL of the last LOS version you had installed.
I don’t know of a fastboot command to query the expected rollback index, funnily enough there’s one to clear it:
Not sure if anyone ever tried it 
Any chance that was before Lineage raised the SPL on December 11?
Otherwise you’ll have to wait a bit for Fairphone to catch up: