Should i expect to happens again ? Also what i need to change the cluster with S4 RB8 Immo3 immobilizer ? With immo off will work plug and play or i need to do something else too ?

s4 is a rb8 immo4 ( not immo3 ) cluster - so you need immo off , and add new transponders , because its immo 4 VCDS won't do anything here ( you need FVDI at least to do it.. or other similar stuff )

propably copy immo data from one cluster to another , There is a little chance that you could adapt it with vcds. Also I don't know how a cluster from B6 will act in B7 ( There are little differences ) - but go for it and try

one I had a similar situation - A4 B7 diesel 2.0TDI multitronic ,  swapped to 2.7BiT and quattro - the owner wanted a s4 cluster , he brought me these 2 cluster - I just modified the original cluster - changed leds as s4 colors , rescaled speed and tacho in dump to match s4 gauge faces etc.