Not necessarily -- these things come in generations. There's not much left after 1GHz A8s -- maybe 1.2 GHz or so -- before the market jumps to A9s. So a certain 4 month gap will see a bunch of 1GHz A8s at the beginning and the end, and another 4 month gap would see the end of the A8s, and A9s taking over, then another plateau with entry-level A9s, etc.. Improvement isn't continuous on a timescale of months. (Naturally, I'm speaking of high-end phones here -- of course lower-end models continue using older, cheaper processors for a while, and this does seem to roll down more-or-less continuously.)

Coming out behind the rest of the market, like an 800MHz when everyone else has been shipping 1GHz for months, would definitely be bad, but I see no reason to suspect Nokia would do that. The leaked specs say 1GHz.