No changes in DNR or TNR in Resolve 12 that I can see. To me, one of the secrets of NR is to noise-reduce the noisiest color channels using a splitter/combiner, or try noise-reducing chroma-only or luma-only (depending on the issue). It's also possible to just NR the blacks using keys, assuming those are the noisiest part of the signal.
Neat is still the best and most time consuming solution next to a proper system like PFCLean, MTI or DCO.
Just buy the plugin and use it in Resolve.
DNR or TNR have limited use to me, but are a great tool to evaluate how much is needed.