Some of my thinking was that so long as the decay was decorrelated multiple copies of the same record could provide redundancy, though that applies to many other candidate media for these kinds of projects as well.

The best option for long term archive is probably still characters printed out on paper, but getting that back into a working system can be quite a bit harder depending on the size of the codebase you want to restore. Of course all these assumptions are probably wildly inaccurate about the relative probably of events, e.g. of someone having a record player and a functional CPU while also not having a scanner. However, another objective here was to reduce the number of steps that had to be performed by a human being that could go wrong. A run of the mill office scanner doesn't quite fit the bill because it might have been cannibalized to be the CPU and because scanning in 40MB of printed pages is much lower bandwidth than the record. So end the end the calculation comes out to be the relative likelihood of having a record player and a CPU but not a modern automated book scanning system, and there the odds seem very much in favor of the record player.

Here it definitely depends on what your goals are. The best records we have from the past, in terms of their ability to survive, are fired clay tablets. Paper records really only survive in very dry environments. (Special documents, notably peace treaties, could be inscribed on metal. But the metal used was generally silver, for its value, which isn't ideal for archival purposes.)

With more modern technology, we can do thinner stainless steel plaques, which solve the problems of tablet thickness and metal rusting. They would also be more difficult to shatter than fired ceramics. Such an archive would survive far, far better than a collection of paper. It would be more expensive, and bulkier.

It might depend on what your vinyl is made from.