I wonder if this [ammo update] might sway people's preferences?
Absolutely.
Even money aside, I used to generally prefer SA80 over AK12, because AK12 had two fewer mags to work with; fewer chances for the commando niche ideal, 1shotting crawlers and trash heads. AK's damage only felt worthwhile when needing to be especially ready for lots of targets requiring multiple shots. (eg solo or bad team)
But now that AK has a mag
more ammo than SA80, AK really feels like an upgrade instead of a sidegrade, better in any circumstance. Grabbing an SA80 for a few waves along the way is a fine option, but when I want and can afford an ideal loadout, I won't be considering SA80 anymore.
There are still downsides, but price is the only one I feel is significant.
AK is slower in full auto and has more recoil, but that doesn't hinder single taps much, and for targets needing multiple shots, the damage more than counterbalances it. Burst mode can make those small downsides into big upsides instead,
at the cost of wasting up to two rounds per target despite your best efforts: good option for tough stuff, bad for trash.
SCAR+AK+Offperk3, or SCAR+Offperk9 will be my usual endgame commando loadouts now.