If rkdeveloptool wl is used to write sectors to emmc of the device, in some cases rkdeveloptool rl command is going to return hex cc cc .. sequence indicating that write did not reach emmc.
This does not mean that writes did not pass, but rather that rl command is not successfully reading the data from emmc storage.
If these blocks are read from Linux/Android OS, the blocks are indeed written by wl.