After the research I did it I have the feeling that the NFS2ISO tool works and does not create broken NFS files. Even the EGGS Header should be 100% correct.
What I believe is the problem is that in the code folder are rvlt.tik and rvlt.tmd. those are the "same" as the ticket.bin and tmd.bin from the root of the Wii ISO EXCEPT that rvlt.tik has a different byte at 0xE that the ticket.bin from the ISO.
Of the 4 games I looked into one was 0x26 vs 0x39, one was 0x47 vs 0x58, one was 0xC8 vs 0xD7 and the last one was 0x92 vs 0x8D.
Edit: Yep changed the byte to the same as in the iso and the Wii U reloaded like always. So this has to be it