The Wiring Framework is not intended to support all functions for all microcontrollers. It is intended to ease the comprehension entry-barrier for working with microcontrollers.
With that said, it will be possible (if/when STM32 support is ready) to have complex libraries and additional code support for things like DMA and RTOS functionality.
If you would like to volunteer to help out with the development of the Wiring Framework on the STM32 series, please do!