Isn't spacetime an all time storage system? You can't burn it, chafe it, erode it. Its is going to be there forever. Even if there's something that you think has been lost(like the library of Alexandria or the Roman empire) is waiting to be seen again. It is never lost. These `movies` of spacetime is being saved on a forever store.
Much as users don't want backups, they want restores, authors don't want books, they want readers.
There's an interesting parallel between transmissions and recordings I'd noticed some time ago, that doesn't seem to be much commented on in discussions of information theory, though I'm not sure if it's because it's obscure or obvious:
A transmission utilises variations in time in a low-noise channel to deliver information over space to a receiver which does not have to move or sweep relative to the signal.
A recording utilises variations in space in a low-variance medium to deliver information through time, to a reader which must move or sweep relative to the encoding.
Each further relies on encoding, decoding, is subject to noise or deterioration, and may be subject to context or inference. Probably other factors as well.
Recordings can, of course, be moved through space (though a single recording can be in only a given location at a given time). Transmissions also travel through time at some rate, not exceeding the speed of light.
There are systems which combine transmission and recording (notably computers). Transmission and recording each play a role in virtually all message chains. And there may be some forms of encoding (possibly holographic?) which either combine both methods or utilise others (though I'm inclined to see holograms as forms of recordings).
"Spacetime" as an all-time storage system, by itself, either doesn't make sense or is so vague as to be meaningless. Perhaps you could clarify.
Also: there's no inherent conservation law of information. Quite the opposite.