It's a matter of the local hotel's policy. I know LCs that show availability online for two-level presidential suites with terrace, etc. and I similarly know of Hyatts that show whether their very special suites are available and the rates.

Especially if the suite has artwork or antiques, I can understand the hotel wanting to verify details and avoid renting the suite to large groups or someone planning a party. They might also want to keep it available in case some true VIP wants to book it at the last minute since walking someone from a confirmed presidential suite or downgrading a guest substantially would look very bad.