Blender 2.9 Basic Extrude Issue Blender 2.9 official
Ubuntu
Basic scene - default cube - no transforms, global orientation
Edit - face select
Select face normal to Y axis - press e to extrude - working as I would expect.
However, if I select the face, then press E, then Y to extrude along the y axis, it goes in Z direction.
Is anyone else seeing this?
Short video of the issue at the link below:
Extrude Issue in action
This appears to be a basic change in behavior - now, when you want to extrude along a global axis you would need to press E for extrude, then Y twice.  Or open the on screen widget and change it from normal to global.

See the post on Blenderartists:
BA Thread