1) Extend Bindless Environment
Adding extensions GL_NV_shader_buffer_load, GL_NV_vertex_buffer_unified_memory, GL_NV_uniform_buffer_unified_memory, GL_NV_bindless_multi_draw_indirect_count, GL_NV_bindless_multi_draw_indirect to
OpenGL 4.6 or as ARB extension.

2) Another way of setting OpenGL state set and rendering
Adding functionality in GL_NV_command_list or familiar.

3) 2D rendering
Why not extend 3D rendering with 2D gpu accelerated rendering as in GL_NV_path_rendering?

Adding support SPIR-V shaders in OpenGL will be wonderful.

5) More powerful vertex shader and geometry shader
Adding GL_AMD_vertex_shader_viewport_index GL_AMD_vertex_shader_layer to standard, GL_NV_geometry_shader_passthrough

6) Extend stencil operands and capabilities
As in GL_AMD_stencil_operation_extended and GL_AMD_shader_stencil_value_export

7) 64-bit variables
As in GL_AMD_gpu_shader_int64, GL_EXT_vertex_attrib_64bit

8) Extend atomic operations
As in GL_NV_shader_atomic_int64, GL_NV_shader_atomic_fp16_vector, GL_NV_shader_atomic_float64