Example: Create a 2/10 Multisig. Destroy one of the 10 seeds. Do I now have the equivalent of a 2/9 Multisig?
Technically, each of your 2-of-10 MultiSig address is a script consisting of 10 public keys and the number of signatures required to unlock it,
When hashed, it produces a specific scriptPubkey (
shown as address in wallets)
Even if you lose the seed of one of the public key, your wallet will still have to include that public key when it needs to unlock that script.
Because otherwise, a script with 9 public keys, even though consisting of same public keys and same number of required signatures
will be an entirely different script and will produce a different scriptPubkey.
So it's still a 2-of-10 in your wallet and in the Bitcoin blockchain.