As Godot 4.0 gets ever closer to seeing the light with an Alpha version, the team has clarified what OpenGL / OpenGL ES support to expect from it since the big thing with 4.0 is Vulkan.
It's looking like there won't actually be any OpenGL/ES support when 4.0 is out, because the renderer went through such a massive overhaul for Vulkan and many new advanced features. A lot of it was done from scratch to make use of new and more modern techniques so they're looking at Godot 4.1 to bring back in official OpenGL/ES support.
However, it's taking a different shape than Godot 3.x. Going by what they said they will look at dropping GLES2 in favour of GLES3. There's multiple reasons for that they mentioned including hardware that can't work with GLES3 being really old, same goes for mobile and even on the Safari browser GLES3 support is now out in a preview form so a lot of the barriers for sticking with GLES3 have been pulled down over the years since Godot 4.0 was in development.
The newer design for GLES3 in Godot 4.0 will take a different shape too with it being done similar to GLES2 in Godot 3.x to allow better performance on older devices for allow for using the newer features to better work with more complex and bigger games.
Godot's team do mention that GLES2 is not dead though, far from it. Godot 3.x is being supported for a long time and is nice and stable while Godot 4.x may see it added later, as contributors do have the ability to work on it.
Overall, it sounds like a pretty sane plan. Game engines have to move with the times.