That is very probable, and I would argue any combine as heavy as they all appear to be should be on tracks. However a drive through the local dealer a couple weeks ago reveals a whole line of new combines on tires! I think the price on these machines is so high guys are cutting corners on the options, and we can be wet in this area. Tracks are great insurance IMO and actually are a serious upgrade for comfort, roading and serviceability.I think the hopper size spread between wheels and tracks will spread out.
From both functional/engineering as well as marketing reasons that high extension seen here will just be on tracks.