You are correct, this is an update like 2015 and 2016, available in digital format only. The difference with the previous updates (and all versions) is that this 2018 update is in full color and has many more charts and visuals. This 2018 update is done and for sale right now, and yes I partnered with Rob Vollman on this version to do all charts, visuals and layout.
At this point we have not had any discussions about future publications of Hockey abstract books. I have not been involved in the Stat Shot books, but from a reader's standpoint I would say Stat Shot is a more generic book about hockey analytics to better understand them, where Hockey Abstract looks at the actual team and player data (mostly from the last three seasons) and writes with a focus on the new 2018-2019 NHL season.
I hope this helps.
RJ