Hi,
I assume from your post that you are not maintaining any user status at NW&NWA level. Am I right?.
In fact you are looking for a solution such that, NWA should not be released when WBS element having CRTD status.
Try this way... create status profile for NWA and check for forbidding REL of NWA if WBS element in CRTD. its not a straight cut but we need to tweak it. User status at NWA is more important for you than at WBS element.
If this requirement can not be acheived through standard customization, then we may have use user exits, CNEX0028 Check activity release & CNEX0029 Check network release. Discuss with your ABAPer to develop custom check to release the NWA if WBS element in CRTD status.
Thanks,
Sudhakar