I would say yes and no.
In the v2 "Reinforced Platoon" you took a leader, two infantry squads and then you could add whatever you wanted, a medium mortar, a heavy machine gun (which no-one took because of the sniper rule), an anti-tank gun, a single tank, etc. The reinforced platoon bore no resemblance to actual WWII force organizations.
In v3 you still take an infantry platoon to start you force (platoon commander and a minimum of 2 squads). You can add a third or fourth squad if you want it to be historically accurate (for ex. German early war infantry platoon was 4 squads, 10 men each; German late war infantry platoon 3 squads, 9 men each). Then you can add additional "platoons" (heavy weapons, artillery, armor, etc.) but in historical terms, these are actually sections from the support companies and platoons that existed all of the WWII armies.
For example, if you want to add a medium mortar, now you have to take a "Heavy Weapons Platoon" with a platoon commander and 2 medium mortars. In WWII German infantry battalions, there was a heavy company that had mortar and machine gun platoons. The platoons had a platoon commander and 2 or more sections with an NCO section leader and 2 weapons. The Bolt Action v3 "Heavy Weapons Platoon" in this case is really just a mortar section (the required "platoon commander" being the NCO section leader). So in that sense, it is historically accurate to the real organization of a German infantry force, it is just the name that is off. The same is true for an anti-tank gun (a section was a section leader and 1 gun) or tanks (a German armored platoon was a platoon commander and 2 sections, each with 2 tanks, 1 of which was the NCO).
The reason I say "and no" is that there are some places in the v3 rules where you can still take non-historical choices. For example, in the "Heavy Weapons Platoon" you can take 1 mortar and 1 machine gun, which would not have been the historical organization of these units. As another example, in the "Artillery Platoon" you can take a platoon commander and 1 medium howitzer. In most armies, medium howitzers (like the German 105mm) were in sections with 2 guns.
I prefer to build my list as historically accurate (I don't play in tournaments so it's not a big deal to me) and I think v3 works much better for that.