I know Google and CF claim they don't track this DNS information, but why even use them when you can run your own. Keep in mind CF did have a software bug that spewed SSL traffic and passwords all over the Internet[1], and they took down a website once because their CEO didn't like it[2].
[1] https://blog.cloudflare.com/incident-report-on-memory-leak-c...
[2] https://fightthefuture.org/article/the-new-era-of-corporate-...