You're right, I may have stated that a little too strongly. The 13" MBP currently uses 8th generation processors, and there are 9th (and / or possibly 10th) generation processors which should be a fit for them. I think it likely that a CPU refresh may occur in October when the newest MBP is introduced, but it's not a sure thing.
(I think the only upgrade path is Ice Lake-U. The parts Apple are using are from earlier this year; there doesn’t appear to be anything else more recent. Neither Whiskey Lake-U nor Comet Lake-U have Iris Plus offerings for now, so those would be a downgrade.)
Ice Lake-U would give them more GPU power, so that’s plausible. But Ice Lake doesn’t appear to be shipping in volume (which is basically why Intel launched similar Comet Lake parts in parallel), so may not be a practical option.