I'd say Oxen Service nodes are quite similar to Tor and its relays operate, it doesn't matter where the server is due to their onion routing.
I don't think you should be worried due to the onion routing.
Even Tor has a disproportionate amount of servers in a few countries in comparision to others: https://metrics.torproject.org/bubbles.html#country
Well...
The first thing that made me go "hmm..." was the fact that the random servers I see whenever I connect are always in handful of countries (US, Germany, France). I would have expected something more geographically distributed, not just in Five Eyes+ countries (although one could retort that hoenypots are easier to install and maintain in low-cost countries, like the Philippines or Moldova)
The second thing, as stated, was the perceived discrepancy between the high cost (physical and emotional) of running a server in a country involved in a very distructive war.
So, as you can see, I'm - well, let's avoid "paranoid" - suspicious all over board.