I think I've shot down about 10 Spits online that didn't know I was tucked up right behind them. So I haven't noticed this at all.
I've also been bounced once in a Spit and never heard anything, in fact when all the damage messages came up I thought I had messed up the CEM. Then I noticed the tracers.
I hope it stays this way. I hated it that in IL2 you can hear the engines, as this favours the T&B crowd. I remember when they took it away in one patch and some of the famous online aces in those days suddenly became easy meat.