I'll tell you what I do not like about this build. Just my personal opinion.
1. No support for high-density RDIMMs.
2. No IPMI.
3. Game-ish case, it lets in too much dust.
4. Just one GPU, albeit rather powerful. Lacks in flexibility.
5. AMD processors are still weak at MKL-related tasks, which are important in DL (particularly data augmentation).
6. I think that with such price, one could get a used cascade lake xeon and a mainboard with IPMI, a better layout, a PLX switch, and RDIMM support.
7. 64Gb of RAM are too few.
8. RGB stuff is useless and just bothers the user.
9. That monster heatsink is gonna put a lot of torsional strain upon socket and mb. Such contraptions should be used with the case laid down horizontally. Or go liquid.
10. You could have used a bit more paste :D
Otherwise, a good machine, but it seems more of a 4K gaming rig for your son rather than a serious deep learning workstation.