My initial impression was that this is worse than just making transient storage patterns cost-effective for SSTORE/SLOAD. But since we have to pay storage gas up-front, the larger issue is that REVERT does not refund (see EIP-3978).
I would rather the gas costs be fixed than for two opcodes to go toward this. The new opcodes won’t fix existing gas injustices like UniswapV2’s re-entry lock. These opcodes just create new complexity to isolate a small portion of new code from the problem, rather than addressing the problem itself.