As long as we don't have facts it is hard to really say if this is true or not, but as Elchino already mentioned we regularly saw 3-4 support weapons in normal builds which seems like a reasonable amount.
The only thing I find a pity is that mortars are not among them, since they seem to be not worth it in 1v1 and partially 2v2.
I just trying to point out that is seem to be quite a recent changes:
WC2019:
Ostheer 40 games, number of units builds/number of games:
MG42 51/33
GrW 34 Mortar Team 8/8
Soviet48 games, number of units builds/number of games:
M1910 Maxim 31/23
DShK 38 Heavy Machine Gun 9/5
Paradrop DShK HMG 1/1
PM-41 82mm Mortar 6/5
HM-38 120mm Mortar 1/1
OKW 61 games, number of units builds/number of games:
MG34 Heavy Machine Gun 93/57
7.5cm le.IG 7/6
USF 44 games, number of units builds/number of games:
M2HB .50 cal 80/38
M1 81mm Mortar Team 10/10
M1 75mm Pack Howitzer 6/5
Air Dropped Combat Group 4/4
UKF8 games, number of units builds/number of games:
Vickers HMG 5/3
3-inch Mortar Emplacement 1/1