Theres so many things that would go wrong here, the biggest one being it's impossible for you to debug any addon due to this without making the addon author have to do more work sorting through your mass file.
This is one of those ideas that it "could" improve load time, but the requirements to do it are so insane that it's not even worth attempting.
But it is technically possible, right?
About debugging: I was assuming this is for a set of addons that works without issue when installed seperately. There shouldn't be any huge difference between having them installed seperately, and just as one big file, right (except load times)?