Yep. Test this first and done.
Next step could be to remove them from cons too allowing them for a bundled molotov and at nade package. CEs are cheap and they should build them.
I'd leave them on cons just because they are supposed to provide utility to the masses and they don't get their upgrade until much much later so they rely on their positioning much later. Kinda like I wouldn't take the bags of ostroppen or the previous version of Tommie. If it's pivotal to the usage of the unit for the majority of their life I say it should stay.
As for the molotov and AT nade combo, tbh imo they are both cheap enough now that it's not a HUGE deal since cons have some ability to perform late game. As a matter of fact I might even go as far as to suggest that 7man require both upgrades even at t4 (no extra side tech tho) just to beef up the cost/ performance ratio of 7 man cons a bit.
Even though I'd personally love to rework the sandbags dynamic, as I think sandbags on mainline infantry was a mistake by Relic (except for Cons), it is simply not feasible to do so at this point. We don't know how long Relic will continue to support the game, every patch can be the last. Sandbags are a huge part of the power level of Volksgrenadiers and Infantry Sections and removing them from these units would very likely require multiple other adjustments/compensations that would probably take 2-3 patches to iron out. It's simply not a risk that can be taken.
I totally get that. Imo tho, sandbags are such a pivotal point of infantry combat and as you say, is a huge part of the power level of the units that have it I think it should be worth a look. Even if it's just a build time change to start on those that... Need them less?
Side note I'm not sure why Relic would abandon coh2 when there is such a passionate community, including a dedicated team of modders trying to tweak what they then selves have given up on. I know it's inevitable but I feel like as long as there is as much chatter and discussion about this old of a game as there is they would be happy keep it at least on life support.