That's the problem.
T70 perfomance nerf honestly is barely feelable, it only cant wipe squads that easy now, but bleed and force them away just as good. Cons perfomance for a 240mp unit is completly fine in early game, they are alright in terms of combat perfomance vs both volks and grenadiers.
When axis get their upgrades, cons indeed do feel lacklaster, but again in case you cant\dont want to support them with either guards\shocks by that time, faster MR giving you an option to get your cons 7th upgrade. Sure you would have a window of disadvantage, but its considerably smaller now.
Nobody ever payed for the upgrade at T3. It's expensive, there are other priorities like bringing in T4 and at T3 you don't even have enough muni to upgrade the squads anyway. Pay the fuel and MP jsut to ugprade one or two squads s incredibly inefficient at that timing.
Idk really, you wont have muni only if you spend it all on mines. Both axis factions, by the time of sov T3 are able to give LMGs\STGs to most of their units and even lay mines. How soviets wont have muni for 4 cons squads by that time.
But again its not the point. You've been given an option to get MR cheaper and faster then in live. By the time you will get T4 up and running, this 20 fuel and 100mp would mean little to nothing in a global picture anyway.
The vet bonus being global doesn't matter. By the time you now get MR, every Cons squad instantly gets ugpraded anyway, you don't have any unupgraded untis running around, and most are about to hit vet 3 already, so there is little benefit. What matters about 7m upgrade is the increased damage output, which allows cons to directly engage Axis infantry, and the 7th model which makes the squads less likely to get wiped when biggest sources of damage become explosive. The 20% XP bonus is useful only for replacing lost squads.
So you want to say that by 6-7 minute mark (because this is pretty much the timing of new MR) most of your cons are vet3? Again, MR now buffs not only upgraded cons, but also cons with Svts\PPSH and penals. Before this MR was free, but completly useless in case you pick something which gave cons any weapons.
I dont understand why you are complaining about it, considering you will be able to face upgraded axis inf with 7th grade faster then before.