Returning to a pre-0.16 world in 0.16 I've found that golden (desert) rabbits are spawning with ludicrously high frequency in all grassy areas of my base. Most of my base is in a desert biome but they also spawn in the jungle parts, and appear to be ignoring the passive mob cap, since I'd never normally get passive spawns in the areas of my base that already have animals in.

It's possible I'm wrong but I was also under the impression desert rabbits should spawn on sand, not on grass? I've seen no evidence of them spawning in any sandy areas.

later edit: I can't reproduce this effect by adding grassy patches to newly created creative world deserts, but if I restore the same old survival world from the backup the problem is the same.