@Kevin3NF asked the question, and @NedOtter added the important clarification that my answer is for the context of on-disk rowstore, since Hekaton tables are outside of the bpool thus bpool dirty pages don't apply.
A question came up on Twitter #\sqlhelp that caught my eye today.
Paraphrasing: After a checkpoint writes a dirty database page, does that page remain in the buffer pool as a clean page?
I thought the answer was yes, but figured I better check :-)
My test code...
And... the results...
Good, I got that one right :-)
Ciao for now!