In a day and age when literally everyone connected to a film production gets a credit, from craft services to on-set teachers of child actors to random “production babies” who didn’t even work on a film, it is utterly incomprehensible that vfx artists, whose work makes possible the final images that appear onscreen, are routinely omitted from screen credits.
I can attest to this, having worked in the field. Most of the work in TV and cinema goes uncredited, with team leaders or just the post houses at most being recognized with an end credit placement (by contract, of course). I understand totally that it is always a team effort and hardly any of the viewing public sits through the entire end credits roll. I totally get it. But when it happens that you are included, that small token of recognition does remind you why you're doing 12-hour days erasing power lines, making day look like night, adding/removing people and/or signage from shots they weren't supposed to be in and pushing greenscreened people in front of moving cars.
As someone who had his name left out of film credits before (actually, it listed the guy’s name who didn’t get the role I got instead of mine), I know how this stings. Sadly film & television is full of neglectful morons, they fuck up, ultimately all you can do is move on.
At some point, when it comes to the way VFX people are treated in the industry, it goes beyond simple neglect imo. These people are constantly being fucked over.
I sincerely doubt it was neglect, but a calculated decision either to support his "no CG" bullshit or to hide the fact they used outsourced CG farms with terrible working conditions.