Mr Norman , pretty much confirmed on the Cardinal facebook page, where at least some posters are employees, or station volunteers.
Some are pointing out The business class car only had 18 seats , due to been 1/2 unused cafe. And that possibly the Cardinal is on the limit for one engine , so it may actually be been removed to allow for another sleeper. Apparently different rules (by CSX?) apply to adding a car permanently , vs seasonally.
For facebookers,
https://www.facebook.com/groups/AmtraksCardinal/
Moderator
worldwide railfan ,
Rail travel & trip reports
The only train trips I regret are the ones I didn't take.