Well the issue has always been that Theater Mode has never been 100%. It is always slightly different from what is seen in game. People use it to try to prove how dead on accurate they were, but it is really just a ghosted image of what happened and not a 1 for 1 representation.
For that reason, I won't miss it.
I've never really used this feature so won't miss it....there are some positives that may come from this..fewer randoms going for their 360 no scope montages and such..
As said by yourself, a shame for those that used it for "innovative material" though.