In the latest Java snapshot, the glow squid can only be spawn below Y=30. However, on Bedrock, the glow squid still spawns above Y=30, especially on rivers/oceans.
Step to Reproduce
1. Find a frozen river/ocean that is covered with ice.
2. Go below the ice.
No glow squid spawning above Y=30.
A lot of glow squid are still spawning just below the ice above Y=30.