Thomas, although iNat exists to encourage people to get out and interact with nature, it is, by its very existence and structure, a de facto repository for the documentation of those interactions. I regard the distinction of past, present, and future records as secondary to the accumulation of this natural history database in its entirety.
Counter-argument: Where is there an integrated, all-encompassing, public repository for those valuable older records? iNat would seem to be the best and most logical repository to make such records available for future researchers.