I noticed that the official 2.1 patch updated this recipe to use their new shared_probability mechanic, but this mod still uses independent_probability. Was this an intentional choice?

As it is defined in Wube's 2.1 patch:

    results =
    {
      {type = "item", name = "iron-gear-wheel",        amount = 1, shared_probability = { min = 0.00, max = 0.20 }, show_details_in_recipe_tooltip = false},
      {type = "item", name = "solid-fuel",             amount = 1, shared_probability = { min = 0.20, max = 0.27 }, show_details_in_recipe_tooltip = false},
      {type = "item", name = "concrete",               amount = 1, shared_probability = { min = 0.27, max = 0.33 }, show_details_in_recipe_tooltip = false},
      {type = "item", name = "ice",                    amount = 1, shared_probability = { min = 0.33, max = 0.38 }, show_details_in_recipe_tooltip = false},
      {type = "item", name = "steel-plate",            amount = 1, shared_probability = { min = 0.38, max = 0.42 }, show_details_in_recipe_tooltip = false},
      {type = "item", name = "battery",                amount = 1, shared_probability = { min = 0.42, max = 0.46 }, show_details_in_recipe_tooltip = false},
      {type = "item", name = "stone",                  amount = 1, shared_probability = { min = 0.46, max = 0.50 }, show_details_in_recipe_tooltip = false},
      {type = "item", name = "advanced-circuit",       amount = 1, shared_probability = { min = 0.50, max = 0.53 }, show_details_in_recipe_tooltip = false},
      {type = "item", name = "copper-cable",           amount = 1, shared_probability = { min = 0.53, max = 0.56 }, show_details_in_recipe_tooltip = false},
      {type = "item", name = "processing-unit",        amount = 1, shared_probability = { min = 0.56, max = 0.58 }, show_details_in_recipe_tooltip = false},
      {type = "item", name = "low-density-structure",  amount = 1, shared_probability = { min = 0.58, max = 0.59 }, show_details_in_recipe_tooltip = false},
      {type = "item", name = "holmium-ore",            amount = 1, shared_probability = { min = 0.59, max = 0.60 }, show_details_in_recipe_tooltip = false},
    }