If port 8333 is closed, will a node relay transactions to its peers? During a recent discussion, it was asserted that a node running Bitcoin Core behind a firewall with port 8333 closed would still relay blocks/transactions to peers. Unsolicited connections would be blocked due to the closed port, but the node itself would still relay blocks and transactions to any connected peers.

I'm looking for a good resource that settles the issue. Where can I find one?
Yes it will, connection directionality will not affect block and transaction relaying.