If the invasion started at the beginning of June, or perhaps on June 10th, they likely miss the Rasputitsa common in May, and potentially will have the ability to get into Moscow in October holding all other things constant.
I think the Kiev diversion was necessary and was actually quite the success. The offensives near Moscow could have worked despite the logistical problems and weather problems perhaps without the diversion to Kalinin.
The question is, do the Germans if they capture Moscow end up being able to keep it? The Soviets brought up the reserve armies for the counterattack and would have been able to do so in this TL as well, and the Germans were at the end of their logistical tail as things stood.
Another big question is the impact of Fuhrer Directive 33 on the ability to advance during the Smolensk campaign. German generals were routinely frustrated that they couldn't advance east even without the dispatched Panzer groups, as they were getting the better of the combat at Smolensk and it wasn't even close, and small scale local encirclements were not enough to satiate their offensive drive. I think if at Smolensk, the Germans allowed for some eastwards movement before the end of the Kiev encirclement reduction, it would have helped push them closer to starting Typhoon from a position where they would get more momentum to take Moscow. Kiev was a great victory for the Germans, but it also was such a massive encirclement that it took longer to reduce the pockets than perhaps they would have preferred.
Finally, I wonder if the slow progress in the South that necessitated the Kiev diversion to begin with could have been prevented perhaps with more reserve forces deployed to Army Group South. The Pripyat Marshes and Carpathians made progress slow, but perhaps, the Germans would have been better suited to concentrate more of their forces in Romania and achieve a breakthrough in Bessarabia and Southern Ukraine while leaving the Soviet forces deployed farther north, which had well equipped Mechanized and Armor units, to be reduced in a strategic level encirclement in concert with Army Group Centre at the beginning of the invasion. Perhaps if this was the case, Hitler may not have needed to deploy Army Group Centre's Panzer formations for the Kiev diversion, and instead, the threat to the flank of AGC would have been reduced early on. This may be a poor analysis of the situation, however.
