I get what you're saying, and I was more than happy with him in the Legends section.  But when they include him in the open, they're putting forth that he's looked at as a member of the roster and a part of the show.

Basically they're saying "Hey look, Rock's a Raw guy!"

And techincally, he's the number 1 contender to the WWE Title, since John Cena is the champion (I know, there's no guarantee Cena's the champ at Mania, but as of now, Rocky's got a championship match on a PPV, thus he should be part of the roster for that alone).

But mainly, since he's featured in the open, that shows that WWE is pushing him as part of Raw.

And if 30 days passes w/o a Rock sighting, then he gets reactivated when he comes back.