Such solder joints are suspect for production purposes. They are hard to inspect (there's no fillet on the bottom, or it's hidden inside the barrel), and may have inferior strength (because there's no blob of solder holding them on the bottom, just a thin ring of copper).
I've done this before: for THT pin tails, and SMT components, on the bottom side, place the board against a squishy thermal pad. This gives the heatsinking benefit of flush mounting, while maximizing usable board area for component placement, without compromising manufacturability.
But it's all a lot of noise on the wind if you have no process and no standard to work to. One-offs? Lab boards? Do whatever you feel like. If it works, it works...
Tim