Young does not specify what the new sizes are, but his tweet suggests that Apple might actually launch one with an even bigger display. This means that moving forwards, the 41mm will continue to maintain its position as the smallest model, at least as far as the more current models are concerned, not taking into account the Series 3 which is still being sold.
Don't be surprised if there are 3 sizes next year…
— Ross Young (@DSCCRoss) October 12, 2021
The 45mm Apple Watch is actually a pretty decent size for those who have slightly larger wrists or for those who prefer a larger display, so we’re not sure how much bigger Apple could go without making the watch too bulky.
There have also been rumors that Apple could introduce a new design to the Apple Watch lineup. It was originally rumored that those designs were for the Series 7, but when the watch officially launched, those designs were nowhere to be seen. It was later suggested that those leaked designs were actually for the Series 8, but we suggest that you continue taking this with a grain of salt for now.