There's currently, correct me if I'm wrong, two weapons in the Menagerie that have been recycled to S11 - Main Ingredient and The Last Dance - both with the tetrahedron symbol. Imagine if each season, "new" things were introduced to the Menagerie.
Fun activity, guaranteed drops, choosing your stats and masterwork stat? Sounds fun to me. Even if we'd have to earn a seasonal currency still, or a specific engram beforehand, I think having the option to do that would be awesome.
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The "problem" with the menagerie as per Bungie, is it was one of the most fun and rewarding activities in the game - but more importantly it wasn't designed by Bungie so they can't have one of the best things in the game to date not made by them still kicking around.