Looked up Relic's changelog when they changed Ubersoldaten armor to received accuracy:
http://community.companyofheroes.com/forum/company-of-heroes-2/company-of-heroes-2-general-discussion/67-coh-2-changelog/page4
The reason given was that infantry received accuracy can be overcome by veterancy (as vet infantry units gains accuracy bonuses), whereas armor does not(as no vet infantry unit gains penetration).
Take note that my suggestion is based on the information I had before where suppression is only added when it rolls a hit. I got this information from the strategy desk when I asked over there last time. Katitof and others say that suppression is not affected by hit/miss and only depends on base suppression value and rate of fire.
Therefore, if suppressions is affected by hit/miss, then my what I suggested would make the MGs more consistent regardless of vet which would stop blobs of high dps units just rushing MG crews all the time due to them not having received accuracy that makes them avoid bullets which means no suppression.
If hit/miss doesn't matter, then this idea of mine will not apply.
I'm not sure exactly which is true but I'm going to believe that received accuracy affects suppression because I can shoot at squads and not suppress them but shooting at a vehicle next to them for 100% accuracy and let the AoE suppression make them hit the dirt instantly.