I wouldn’t categorize them that way, no. NuBits are not a direct financial derivative of NuShares, unlike the relationship between BitUSD and BitShares. NuBits are digital assets that are issued by NuShareholders, where shareholders attempt to maintain a $1.00 price peg as long as possible.
For reference, the FAQ: https://nubits.com/about/faqs#why-are-nushare-dividends-paid-in-peercoin
To answer your question, no, there is no conflict of interest. NuShareholders chose Peercoin as the cryptoasset to distribute dividends in because it is more sustainable than Bitcoin. NuShareholders can vote by motion to use a different external cryptoasset if they wish. Nu and Peercoin are entirely different networks, even though some developers choose to contribute to both projects.