Hi Amine,
The delta will be lost.even if you have deleted the init and created it immediately.
what ever delta records which were available in the delta Queue is flushed when you delete the init. On performing the reinit a new pointer is set. In effect the delta records are lost.
Hence you can wait for the next delta and check whether there is any delta which is missed. if yes then you have to fill in the setup tables and bring the data into BW
Regards
Vivek