There is a bug in Grasshopper, where the Linetype Table doesn’t update until you open the Linetype panel in Rhino once. Before that it is just an empty list:
Oh, I see. I would say it’s not so much “by design”, but “by limitation”. Design would suggest it was consciously decided to do it like that, but it sounds it was done like that because of the bloat.
I am sure there could have been a workaround though. I don’t want the linetype table to always update, but if there is a component called “Query Model Linetypes” you would think it could do the same as opening the Rhino panel.
It seems like the real limitation is that the linetype table can only be loaded by opening the panel, but not any other way? Otherwise the Grasshopper component could trigger that.
I would still class this as a bug, even though it was by design.