Not “significant” though. Man City sold like £50m worth of players (think 4) in that window to Soton, none of whose had played for the senior team. £1.5m is a snip. Even discounting the tax for English teams
They sold him for around £1.5m. Considering it was in the same window where they sold Lavia (who also hadn’t played for the senior team) to Southampton for £20m I’m not sure it can count as a “significant fee” in any way