But from a technical perspective it seems like they could run a pruned node just as well, since they only care about current transactions. Or would a mining pool be prevented from publishing blocks if they are not connected to the network as a full node?
Something tells me they might not get accepted if they don't run a full node.
Why not?
A valid block is a valid block. The protocol and the rest of
the network doesn't care how that block came into being,
nor does the network know how that block came into being.
Or they'd get DDoS a rediculous amount if they tried to get away without running one.
How would you know if they are running a pruned node or not?
What is forgotton is that miners should also be the main node runners and they should be able to distribute the blockchain.
Miners should create valid blocks. That's all. They are welcome to run full nodes and distribute the blockchain if they want to, but there is no requirement for them to do so.
And why wouldn't you want to distribute it if you are earning money from it already and a greater seeding of the blockchain might make more people get into it.
Perhaps you are only trying to make a quick profit, and don't care about the long term viability?