taproot – Is it potential to revoke a spending department after a block top?

I desire a coverage that behaves like so:

• Earlier than block 1 000 000 → spendable by a 2‑of‑3 multisig quorum (keys A, B, C)
• At / after block 1 000 000 → solely spendable by a unique 2‑of‑3 quorum (keys X, Y, Z); the A/B/C path ought to be disabled.

A naive Miniscript try is:

andor(
  ln:after(1000000),       // top test
  multi(2, X, Y, Z),       // “after” department
  multi(2, A, B, C)        // “earlier than” department
)

However I consider after() can solely add situations; it can not make the sooner A/B/C department completely invalid. So each 2‑of‑3 quorums stay usable endlessly.

Is my understanding appropriate, or am I lacking one thing? Does it require a brand new opcode/soft-fork to “revoke” earlier spending situations?

I desire a coverage that behaves like so:

• Earlier than block 1 000 000 → spendable by a 2‑of‑3 multisig quorum (keys A, B, C)
• At / after block 1 000 000 → solely spendable by a unique 2‑of‑3 quorum (keys X, Y, Z); the A/B/C path ought to be disabled.

A naive Miniscript try is:

andor(
  ln:after(1000000),       // top test
  multi(2, X, Y, Z),       // “after” department
  multi(2, A, B, C)        // “earlier than” department
)

However I consider after() can solely add situations; it can not make the sooner A/B/C department completely invalid. So each 2‑of‑3 quorums stay usable endlessly.

Is my understanding appropriate, or am I lacking one thing? Does it require a brand new opcode/soft-fork to “revoke” earlier spending situations?