It won't make it completely redundant, but in most cases having an extra battleship over a cruiser in your fleet would be preferred.l
Cruisers tend to stay at range in fleet battles, so often they survive quite long, and are used to pin whatever's left of your enemy's forces once the battle draws near its end. Depending on the way the fleet is put together, sometimes there will be no snubs left towards the end.
They can also be useful for solo-patrolling if you are careful - in the Tau's there are a lot of miners with battlecruisers that shoot at traders going to Malta. To patrol and properly counter these alone a cruiser is needed.
Also a cruiser is not that OP a ship on its own - a couple of bombers or gunboats can take it down, and it doesn't have flaks (well the battlecruiser does, but I dont have one), so it is somewhat vulnerable to novas. They can be dodged and CM'ed, but only for so long. If you have several bombers with novas, a cruiser will die fast. It is a fun ship to fly and a fun ship to kill.