“Inspired by” means that it draws inspiration from… This implies that both characters from the M&M world and elements that evoke the M&M world may be used, without necessarily being a direct continuation of it… There are similarities in the plot and numerous minor “easter eggs,” some of which are apparent even in the general description (as is the case now) and within the RPG itself. It’s also “inspired by” because many of the races described on the forum and theoretically possible in Heroes are also featured there.
If I wanted to describe an RPG based on M&M, I would have written RPG based on M&M…