Thanks for the tip, Haze! 
Maybe the best choice is proceed as follows:
- if the new version is only a bug fixes, the new version will replace the old version;
- if the new version has changes in levels/gameplay or it adds new options/features, both will be kept.
If it costs you nothing to keep an older version preserved, I'd suggest keeping all the older versions.
Not all bugfixes are 'positive' some end up introducing other issues, sometimes old playthoughs of a game depend on a bug, and end up looking 'impossible' later.
I'll share a little story...
A few years back I was working on a mobile game, it had a score / time attack mode with replays, it would upload players scores and their runs to a server, so that they could be viewed by anybody else.
We got the occasional report of the game crashing mid-run, unfortunately as crashing was fatal, we didn't get the run files for any game that crashed, so the bug sat there for about a year unfixed, we weren't even sure if it was just a hardware bug on some devices.
Eventually we manged to get a solid reproduction. There was some bad code in our game that would trash the state of other objects in memory in a predictable way. If it happened to corrupt the wrong data (pointers to certain things) the game would crash. If it instead happened to corrupt other things (number of enemies left to spawn etc.) the game would continue, seemingly as normal.
We fixed the bug.
Most of the top 20 high score replays that had been uploaded to the servers and shared stopped working.
Those high score replays just happened to be triggering the bug in a way that was changing the behavior of the game (causing less enemies to spawn) thus allowing the players to complete the game more quickly and obtain higher bonus points. The top replays were all relying on a bug in our game code corrupting the game state.
As the replays no longer worked, and the top scores were technically not valid, we ended up deleting them. This caused massive fallout with the player community, accusations of us censoring scores, deleting scores of players for no reason in order to try and make 'our friends' appear higher up etc. Even accusations that we hadn't fixed a bug in our code, but introduced one and were trying to hide that by deleting the replays.
Unfortunately with these closed platforms you can't offer old versions of your software easily. There was no way to restore those replays, that depended on a buggy version of the game, to working state, they were literally 'impossible scores' on the fixed version of the game. People wanted the old version, and the old scores back, that didn't happen, the community abandoned the game.
With an emulator, and a database of versions, you can easily offer all released versions, and let the user pick.
So yeah, if something can be archived, I'd highly recommend archiving it, because you just never know, even obvious bug fixes, for game-crashing bugs, can sometimes have unexpected side-effects if people were relying on those bugs.