Tbh I think this particular mutation will likely be fine re vaccines. I think the main concern for people like myself however is the pace of these mutations. I know it's normal, but it's still notable. We only officially announced the UK variant at the start of December. Two months later we've had the South African one, the Brazilian one and now even the UK one has mutated again. All capable of reducing vaccine efficacy. Given the shittyness of everything, it's not really unreasonable for people to feel cynical and expect the worse - further mutations, with one inevitably handing us a shit sandwich and an even bigger reduction. Might not happen of course, but you can't blame people for being concerned!
I know you hate the word 'could', but everything related to the future in this thread is a guess. It's all we can do. Some have a more cynical world view, some don't. Life.