So you spent a lot of typing to admit the Army hasn't done what you said they did.
The HK rifle allowed the Marines to issue suppressors to pretty much every person in combat arms. Which is a big thing.
You mean as in something like this?
The Marines already deploy drones extensively. In fact iirc the Corps was the first Service to utilize the modern UAVs. I turned down an assignment to the unit.
The fielding of a new rifle hasn't prevented the Marines from also looking into new LMG/HMGs to replace the M240/M2. Weapons utilizing the recoil reduction technology shown in the NGSW trails. They are also looking at the .338 machine gun that SOCOM adopted.
Why inflict a heavier/more expensive weapon on a squad. The AT4 works just as well as the GarlG. Which until recently was only issued to Army spec-ops/Rangers and yes Marine Raiders.