nope. flashing of the bootloader does exactly that, flashing of the bootloader. as does radio, and recovery fwiw.
Did it last night. Found that replacing bootloader and radio were fine, performing the update itself ok, but stuck in bootloop. Only way to get out of it was to re perform the update using -w to wipe everything during the flash. I did attempt to re flash cwm and just clear dalvik and cache, but didnt fix boot loop issue.
Long story short, when switching from different builds and/or updating bootloaders, it wipes the user data.
Best part was, the phone restored everything except 1 game's saved data and 2 apps from how it was before