is cgm + nzge rebalanced available?

I don't think It is yet...

The CGM Rebalanced datapack is still a work in progress, and (with the existence of CGM Expanded) will be further split into two projects:

1. Datapacks for base CGM, which closely follow the original plans for CGM Rebalanced.
2. Datapacks for CGM Expanded, which uses new features from Expanded to overhaul the behavior of the CGM and NZGE guns.

Both projects will have CGM + NZGE and Standalone CGM versions, since the +NZGE versions change some of the CGM guns to use Medium Bullets.

when is nzge 1.5.0 gonna be released?

Sooner or later, IDK when though