The difference between P2SH and Pay to Witness Script Hash (P2WSH) is about the location of what was previously in the scriptSig, and the scriptPubKey being modified.
The scriptPubKey is changed from:
OP_HASH160 <pubKey> OP_EQUAL
With what was previously in the scriptSig (signature + redeem script), moved to the witness. P2WSH uses ScriptCoin in exactly the same way to be signed as in P2SH.
P2WSH in Trezor and Trezor Wallet
Trezor doesn't supports P2WSH yet.