"Prior to the assault on Berlin, this formation's tank companies were completely re-equipped with new M4A2 Sherman tanks, handing over their T-34/85 vehicles to other units of 2nd Guards Tank Army."
Ignoring how it's completely unreasonable for an experienced formation to swap over all of their tanks before a pivotal battle, let's look at the composition of the 2nd Guards Tank Army prior to its offensive on Berlin.
"Tanks and SPGs in the Army on April 18th, 1945
1st Mechanized Corps: M4A2: 165, ISU-122: 21, SU-85: 6, SU-76: 16, total 213 vehicles, including 5 M4A2 tanks in repairs.
In total, the Army has 630 vehicles, of those T-34: 260, M4A2: 184, IS-2: 38, ISU-122: 41, SU-85: 11, SU-76: 75."
As you can see, the 1st Mechanized Corps does indeed have no T-34s left, but the two other corps (both Guards formations, so no quarrel about eliteness here) are full of them. Clearly, the Red Army thought it was perfectly fine to have T-34s attacking Berlin. But what about the other claim? Did the 1st Mechanized Corps really trade in all their T-34s? Let's rewind the clock a little bit.
"Composition of the Army units:
1st Mechanized Corps: 37th Mechanized Brigade: M4A2: 10, 19th Mechanized Brigade: M4A2: 4, 35th Mechanized Brigade: M4A2: 17, 219th Tank Brigade: M4A2: 22.
In total the corps has: M4A2: 72, MkIX: 2, SU-76: 17, SU-85: 11, ISU-122: 13, total: 115."
March 11th, 1945, the unit still has the same structure: a bunch of Sherman brigades supported by light, medium, and heavy SPGs. There are no T-34s here to trade in.
Let's go further back still.
"By the end of September 11th, 1944, the Army units have the following vehicles:
1st Mechanized Corps: 15 M4A2 tanks, of them 2 in minor repairs, 11 in medium repairs, 2 in major repairs, 30 MkIX tanks, of those 15 in medium repairs. These tanks were received on September 10th and 11th after factory repairs."
Way back in September of the previous year, long before anyone was planning an offensive of Berlin, there are still no T-34s here. The only tanks the 1st Mechanized Corps lost between then and Berlin were the Valentine MkIXs.