Good theory. Apple TV with A12 and 32GB replacing Apple TV HD ($149) on the low-end and Apple TV with A13X and 64GB (perhaps bumped to 128GB) replacing Apple TV 4K ($199) fits into their narrative.Let's wait and see but with the quality of the current one along with Arcade, it's highly unlikely that Apple would cut corners and fit a basic chip UNLESS they decide to sell a basic ATV 4K with A12 @ £149 and the ATV 4K Pro at £199 aimed at enthusiasts and gamers?
Either way, I would hold on getting the current Apple TV 4K unless it is heavily discounted on Black Friday (or AT&T brings $90 deal again).