It was due to the change in IRS guidance on how to account for increases in value in cryptocurrency -- in short, treating it closer to a forex exchange (where the value is continually accounted) instead of a securities transaction (where the value is accrued when sold). The value then had to be retroactively accounted for.

Yeah, pretty much. The value increase of Tesla's bitcoins since 2021/2022 was being ignored for accounting purposes until just now.