No, as you are changing firmware so you will overwite any AACS keys present.
It has nothing to do with the BD drive itself per se.
The FW (PS3 not BD Drive) contains the whole AACS functions/procedure etc so when you put a disc in, the drive will check those two self file I mentioned earlier (maybe more?) to see if the keys are valid for the MKB etc. on the disc (this is assumption btw) and if so, update the driver DRL/HRL etc. as well as the Data Revoke folder in devflash3.
Once everything matches and is up to date, the disc will play and be decrypted
If not, you are prompted to update and/or get playback prohibited etc.