Creation/modification dates

Roam stores creation & modification times on every block, which you can see e.g. by hovering over a bullet, and can access via the API or queries.

I was just surprised to see that freshly syncing my Logseq Sync graph to a new computer shows all pages as created and modified at the time of the initial sync, which made me start poking around more, and I’m wondering: does Logseq reliably keep creation/modification dates on anything at all? I’d really like block-level precision, but at minimum having page-level metadata is critical.

Unfortunately no. At this time metadata is lost upon re-index as well as what you experienced yourself.
As Logseq doesn’t store this metadata in the files itself and a new device or re-index build the database purely on the information within the files.
As I understand this might get solved with the database version of Logseq, but I don’t know more about that.