PlatformIO must create a board definition file (JSON format) to create support for a certain board. Not all STM32Duino listed boards currently have an equivalent in PlatformIO – that’s tracked in Support all boards that the STM32 Arduino core supports · Issue #559 · platformio/platform-ststm32 · GitHub (and was also previously tracked in various smaller per-board issues)
I notice you have recently upgraded STM32cube support is Arduino next?
The used Arduino core in PlatformIO is already the latest stable 2.0.0, those files do not need updating.
This also means that one can write a board definition file and reference the wanted chip variant themselves. An example of that can be found in Nucleo_f446ze does not support Arduino framework. Looking for advice, where support for the “Generic F446ZETx” board is added with one board definition file (which is basically one file copied + two additional entries).