There is also the worry that back line drone carriers are way to vulnerable and high value, so haveing every tank have it means its basically impossible for the enemy to take out you long range fires/drone suport.
Drone carriers are not high value though, there is almost no cost in the box launchers. You may not need to fill them with munitions if it is unaffordable.
Back line non-LOS forces benefit from concealment: you can put box under forests, inside garages or hell, inside every building to be pushed out via hand cart, under small camo nets or buried lightly as long as door mechanism can push aside the soil covering.
A box launcher also naturally enables ease of creating decoys. Just have field assembly of boxes from walls that mimic signature of a real drone launcher and very easily one can have 10:1 or 100:1 decoy to real launcher ratio. The boxes can be placed on the ground or put on any and every vehicle.
Distributed lethality makes perfect sense here. Even light UGVs or duck taping it on top of self driving tesla's would do.
------------
The idea that the MBT needs to carry loitering munitions basically follows the logic of singular vehicle force structures. If you think about standard combined arms formations, any MBT would be accompanied by IFVs, Infantry, recon, Air defense, command, logistics and other assets which a loitering munition may be more suited for.
Now it can be argued that other assets are too lightly protected to survive on the modern battlefield, but that is a argument for increasing protection to other assets and not have a force consisting of a singular vehicle type that despite attempts at generalization are extremely weak in many aspects of ground warfare, for example air defense.
Loitering munitions cut into vehicle volume that is especially precious due to armor, and the system operator would spend considerable time and attention focused on the distant battle dozens of kilometers away instead of close combat of a LOS platform. There is no synergy here.
A MBT with loitering munition is the kind of design not dissimilar to battleship-carrier hybrids. There is the new hotness of flying widgets, so lets put it on a legacy concept with completely different concept of operations!
(I think future loiter munition support vehicles will generally have recovery and refuel capability)