I highly doubt there is any prioritization towards a specific connection type. It just doesn't make any sense, especially not sending small updates only through WiFi (if you subscribe to the church or "mobile data is still very expensive for corporate").
If I was to distribute software packages, I would choose the connection based on Speed (Throughput) and responsiveness (Ping), as they usually indicate the stability of a connection. Now if I had a contingent of, say, 3 GB on mobile and had a 5G package to send, I might go to a forced WiFi connection.