No. The transcripts are visible for users with 10k reputation networkwide. If some specific messages are deleted, there is no way to look at them unless you're an Room Owner or a moderator. These users with 10k rep networkwide can also handle spam/offensive flags raised.
The reputation earned varies for three chat servers. To see deleted rooms in chat.meta.stackexchange server, you should earn 10k on Meta Stack Exchange. Reputation on Stack Overflow and other sites do not count. Same with stack Overflow. But your reputation on SO and MSE will count towards your network wide 10k rep on Chat.stackexchange server.
To look at frozen and deleted rooms, select show frozen/deleted rooms
Here's an image how they look after selecting show frozen/deleted rooms.
The faded dark rooms are Frozen rooms. The ones which are pale and white are deleted rooms either by a moderator or due to inactivity.
Frozen rooms have a message "This room is frozen; new messages cannot be added." but deleted rooms do not have this message.