> Is STM32 still in shortage?

In some cases they've never been. It depends on the series. A lot of their portfolio is being made in external fabs like TSMC, whose allocations they gave up when Corona started as they were thinking the chip demand will go down. (Oh boy were they wrong.) On the other hand they still had allocations (in their "own" fabs), so depending on what you want they deliver. Problem is basically anything "mainstream" was in external fabs, e.g. the entire STM32F0 to STM32F4 series. In contrast, if you want an STM32L0 oder STM32L4, you can still order like nothing happened.