Soviets would be better off not disbanding their cavalry formations to the same extent as OTL pre-Barbarossa, IMO.
Their cavalry divisions were a workable substitute for motorized formations, and with soviet logistical problems of OTL they're better suited for maneuver warfare than other branches of RKKA.
Later on, once their logistics improve and more trucks are available, reformation of cavalry into motorized and mechanized divisions would be done; But such reforms are not in the cards pre-Barbarossa.
I'd agree with this if they used their cavalry divisions in this manner, as relatively fast moving infantry divisions, and yes, the potential for motorization once Lend Lease kicks in is certainly there. The problem is that the Soviets did not do this. There was a focus later on of using them as breakthrough (sometimes in the 3rd or 4th attack echelon) troops for strategic offensives in which they were quite useful particularly in the Southern front once the war entered the Balkans, but at the start of the war, this is not how they were used.
In 1941, they were often detached for raids in the Southwestern Front during the Kiev campaign (which were disastrous non-starters), ordered to attack as the second part of an echelon along with doomed Mechanized Corps counterattacks near Smolensk (usually long after unit cohesion had broken down), and generally speaking were about as poorly performing as most Red Army units were, but with the additional logistical nightmare of supporting horses that were combat ready in the field (which was ultimately why they were disbanded in huge numbers in 1942 and turned into Rifle Divisions), which believe it or not, was almost as tough for the Soviets as supporting their spare parts starved Motorized and Tank formations. They ran out of horses, and quickly, for use in a combat role; the Soviets did not employ cavalry in headlong charges or anything near as foolish as that, but they required horses for mobile artillery batallions and for transport of mounted troops in poor terrain while under fire, and these kinds of horses are not as common as one may think. An unfortunate and grisly part of this is because of the massive food shortages the Red Army dealt with before Lend Lease really started kicking in (I would count the food aspects almost as important as the motorization aspects for Soviet success) led to horses being rather appetizing targets for frontline troops in the winter of 1941-42.
The tactical use they were employed for later in the war was fine, but the Soviets early in the war did not need specialized breakthrough troops to carry out deep battle alongside mechanized and shock army formations. They needed troops who could hold a position, and could quickly react to breaks in the lines to throw back the enemy. The Mechanized Corps they had in 1941 actually were not poorly suited for this and had a decent mix of infantry to tanks (albeit with a horrific spare parts problem), but there just were not enough of these nor were they fighting in more concentrated groups. Rather, cavalry corps were expected to bridge the gap and they were poor for this