So, obviously Hitler and his military advisors were well aware of the huge risk, nonetheless they took it.
The explanation given in the recording (Who could have known that they could have produced over 35.000 tanks? Of which we have destroyed 34.000.) is an obvious exaggeration (the total number of all armored fighting vehicles was around 25.000 [2] at the time of the invasion) to deflect from major failures in strategic considerations e.g. underestimating the ruthless adaptability of the Soviets given their gigantic resources of land, oil and fighting men.
Because it is only when the Soviets got invaded they really began to ramp up the production of the legendary T-34 (from 3000 in 1941 to 15.000/year (!) until the end of the war in 1945) and their vast geography helped them to relocate more than half of the production sites from the West to the Ural Mountains way out of the reach for the Germans. So, the Blitzkrieg which worked brilliantly in Western & Central Europe got stuck at Stalingrad into a slow grind. Resulting into the broadest land front in military history with about 10 million military deaths on the Soviet side and about 5 million on the German/Axis side.[3]
Again, why the high risk? The necessity to secure oil fields?[4] Yes, but only paired with the pathological paranoia towards anything "bolshevik" as is evident in the recording. So the recording is not only superficially remarkable as we hear Hitler's normal voice but also quite revealing about the rationalization taking place at a crucial point on the Eastern Front in 1942.
[0]https://en.m.wikipedia.org/wiki/East_European_Plain
[1]https://en.m.wikipedia.org/wiki/French_invasion_of_Russia
[2]https://en.m.wikipedia.org/wiki/Soviet_combat_vehicle_produc...
[3]https://en.m.wikipedia.org/wiki/Eastern_Front_(World_War_II)