I have been playing with my friend who doesn't own lightfall and they have done 4 vex strike forces in a row and haven't received new exotics at all. They have always been duplicates. Meanwhile every time I do it (and I own lightfall) I get exotics I don't have yet (lost sector exotics). If this is because they don't own lightfall, this is ridiculous! It is a free event for everyone. I can understand it not dropping the new exotics (from lightrfall), but the old ones in lost sectors? Feels like another aggressive monetization or a bug. Either way needs to be clarified or fixed.
I think it also doesn’t consider collections. I have everything unlocked but sometimes play on PC where I only have Shadowkeep and I only seem to get Y1 exotics. Not worth doing unless I’m on my primary platform.