That seems to be the case recently, but I for one am glad Shirt Pocket software is taking their time. If you read the blog, it seems that there are always some issues that keep "pooping" up with the beta testing. But as long as they get it right, I am happy.
As it is, Micromat is even slower in getting a version of TechTool Pro ready for a new Mac OS. In fact, it seems to be getting later and later. For Sierra, it was November 2016, for High Sierra it was December 2017, and for Mojave, it was January 2019. The issue is that Apple does not release enough details early on in the development of the new Mac OS, and also the new APFS that was introduced with High Sierra definitely was a challenge. And TechTool Pro is the ONLY maintenance/repair third party product that works fine with APFS. Drive Genius, and even the venerable Disk Warrior, still have issues with APFS.
Finally, I have yet to see anything "earth shattering" in any new Mac OS that I need to have right away. I am content to wait for the .2 or .3 release, so that just about all the bugs are worked out.