You use the word need when you mean want. Why does the game need planes that will be hangar queens? Why do you want planes just to "fill holes in line ups"? That's the weakest argument for adding a plane.
Not so much. The MA is well stocked with planes that keep the masses content if not happy. In that arena there
will always be a 'hangar queen' ratio of probably 40%+ (ignoring that there are players that fly some of them making
those planes seldom used instead of just hangar queens). That leaves events. Scenarios. As long as there's still
subbing going on, there's a need for event aircraft and vehicle sets to have more models. BoB currently has late war
88s versus the right version. That's isn't, by far, the only example.
If HT didn't think events were important I doubt he would take the effort to provide SEAs or the AvA.