Two articles citing a discussion with Robert Davis:
"Currently, the Japanese carmakers offers a larger V6 engine on its Mazda6 sedan and CX-9 crossover, but that won't be the case with their successors. Speaking to Car & Driver magazine, Robert Davis, Mazda’s senior vice president of U.S. Operations, told the publication that it has no plans to develop a next generation V6 under it SkyActive program.
Instead, it will focus on making its larger cars lighter and offer turbocharged versions of its four-cylinder engines."
"Like Volvo, Mazda appears to be moving towards an all-four-cylinder lineup. There are no plans to replace the V-6 engine currently used in the Mazda6 sedan and Mazda CX-9 crossover, and no SkyActiv six-cylinder is currently under development.
Instead, the next Mazda6 will be powered exclusively by four-cylinder engines (including the expected Mazda6 Hybrid), while the larger CX-9 will likely get a turbocharged four-cylinder as its base engine."
The first article worried me, but the second article held out some hope of retaining the option of a V-6.