Developers often have issues with module script memory leaks, like in this topic Memory leak: Modulescripts never Garbage Collected after Destroy()'d and all references are removed.
We receive other reports similar to that and many people are actually surprised that Destroy doesn’t free memory.
In practice, not a lot of developers require destroyed modules and those who do (for example by using HDAdmin) require them after calling Destroy, which this change doesn’t address as it’s not the common memory leak situation.
Common case is that any ModuleScript result containing any functions is never garbage collected, even if the ModuleScript is destroyed.
local module = {}
module.t = table.create(100000, 1) -- some big data
-- every function holds a reference to 'script' because getfenv can be called on it
function module.foo() return 1 end
return module
Since modules are often used to return functions, this is an issue for experiences cloning modules or just having modules in StarterPlayerScripts.