Regarding why Daniel Bryan is in the WWE Intercontinental Title Ladder Match at WrestleMania 31 instead of the WWE World Heavyweight Title picture, it's not that WWE don't see him as a big part of the company or a top competitor, but one of the reasons is that there is still major concern over his health.
Bryan chose to undergo a unique form of rehabilitation for his injury last year and there is a strong fear within WWE that his injuries could become reoccurring issues due to the rehab he did. There's concern that the rehab Bryan chose is not a long-term permanent fix and just a short-term fix that could cause the problems to relapse.
It's likely that Bryan would be in a more prominent position at WrestleMania this year if WWE officials weren't worried that the elbow issues will come back.
Bryan's situation was compared by one source to Kurt Angle having several non-invasive surgeries on his neck years ago but over time Angle ended up having a lot of other issues stemming from the neck injury.
Source: http://www.wrestlinginc.com/wi/news...s-really-concerned-about-daniel-bryan-future/