I think we nee to realise that software development is way ahead of its release cycle. I would be surprised if they were not already well on the way to what X4 will be. Along with that they will have interim goals for various updates that usually include not just fixes but some smaller new features that perhaps weren't ready at full version release time.
There will always be a group of people who will risk buying the last iteration of a version because they buy late in the cycle. Sonars history is that most updates occur in the first 6 months of the annual cycle with a further 6 months or so till next version.
You can be sure that Gibson had nothing at all to do with the X3 release, in fact we are yet to hear an official announcement declaring that the intention to purchase has been completed and become reality. I've stated my opinion several times and that is that X2a was a fork in the coding road and continue developing what was essentially a useable and stable platform for most users was pointless considering the depth of coding that was required for VST3 and ARA implementation.
So it is sad that some got "burnt" but it's the same story every year. As the Cakewalk staffers have said, anyone who upgraded to X2 late in the cycle likely got it a heavily reduced price and any new users getting in on the ground floor with the full version will be eligible for a reduced upgrade as is any current user.
I mean there was someone on here a while ago claiming they were due special consideration for an x3 upgrade as they had just bought x2 a week before the release. They paid $49 for x2. Now if you had skipped x2 and gone from x1 to x3 you would pay $199, same cost. Of course I'm talking at the Sonar Producer level.