Clean mod for minetest https://forum.minetest.net/viewtopic.php?f=11&t=2777

init.lua

local old_nodes = {"mod:block1", "mod:block2", "mod:block3"}
local old_entities = {"mod:item1", "mod:item2", "mod:item3"}

for _,node_name in ipairs(old_nodes) do
    minetest.register_node(":"..node_name, {
        groups = {old=1},
    })
end

minetest.register_abm({
    nodenames = {"group:old"},
    interval = 1,
    chance = 1,
    action = function(pos, node)
        minetest.remove_node(pos)
    end,
})

for _,entity_name in ipairs(old_entities) do
    minetest.register_entity(":"..entity_name, {
        on_activate = function(self, staticdata)
            self.object:remove()
        end,
    })
end