At the top of the letter it says "SSP" "Special Service Program" and then later at the bottom of the letter says
visit https://www.mazdarecallinfo.com/ to review recalls AND service campaigns. I think this still falls under service campaigns, not a formal recall.
Recalls are BIG news and even BIGGER costs - the government agencies get involved and it is a big to do. A service campaign or service bulletin is Mazda's way of saying 'yeah we got an issue, it is not dangerous, and we are such a great company we are gonna proactively notify owner's to take care of it." "No need to look our way governmental entities we got it under control."