It might describe a shift in a franchise (like a gritty reboot of a cartoon) where the "entertainment content" is being aged up or "matured" for a legacy fanbase.
It often refers to how a piece of media handles adult themes (like violence or complex social issues) within a format typically aimed at younger or general audiences. foxxx matures
"The way popular media matures is by moving away from binary 'good vs evil' tropes and embracing the moral gray areas that define real adult life." [1] It might describe a shift in a franchise
It is frequently used in essays discussing how popular media shapes or reflects the maturity levels of its audience. Community Perspectives foxxx matures