If it never hits flash that might work, but if it's in flash storage then the block may not be erased by the time its dumped.

I'm not sure precisely how the NAND controller responds to requests for raw data from blocks with "deleted" data. And if this would require decapping the flash.

Some flash will happily let you see the data and delay erasing it.

Generally flash is non deterministic about when blocks even those with entirely stale data are erased . It might be years before the block is reused due to wear leveling algorithms and it might retain data that entire time.

Here's hoping the controller for phones which hold sensitive data are more active