I'm looking to use the sleeper in April, so I thought I'd use the website to see what my options are.
It seems that after the 23rd February there are no 1st class options as such, just a choice between 'Classic Solo', 'Classic Shared' and 'Seated'.
It then states "Please be aware that you are booking to travel during a planned transition period while we introduce our new trains. As a result, we cannot guarantee whether you will be travelling on our new train or current train".
I think I'll hang on for a while to see if there is more clarity as, if the opportunity is there, I'd like to book one of the new en suite 'Club Rooms'.