This is obviously a terrible idea.
We had a hot act the fans actually liked and could get behind, an act that had not even won the tag team titles yet...and they've been split up. The idea is now to make Cass a monster heel at the expense of Enzo, even though he's green as grass and clearly worked better in a team where his weaknesses could be concealed. This naturally raises the question, well what about Enzo? What happens to Enzo after this? This answer from WWE management is going to be "who cares." Pretty amazing given that on the mic he's literally the best in the company. A business built 50% around promos, here's a guy that's actually THE BEST at cutting promos, and he's an afterthought.
I'm not against pushing Cass as a singles star, I'm against making him a monster heel. For fuck sakes they need to be more creative than this. Why not keep them both as babyfaces and move Enzo into more of a mouthpiece/manager role, it would still help protect Cass and allow him to be singles star at the same time. Also you wouldn't be completely killing one of the very few things your fans ACTUALLY LIKE.
On a side note, I'm also an advocate for a Big E singles push. I think he's great. But that doesn't mean he should turn on the New Day and become a monster heel. The New Day allowed him to show his natural charisma and legitimately got the fans behind him as a hot babyface. Some common sense is NOT TO KILL THAT GIMMICK. Ride the momentum and carry it forward into a singles push. Not everybody is Triple H. Killing babyface DX to give Triple H a heel push did eventually work, but that was an era where Rock and Austin were both peaking as babyfaces. This is the era of no top babyfaces.