Another key aspect we don't yet know is the duration of the immunity protection these new vaccines. I tried to explain that in the prior thread, but I was admittedly wordy. If the new vaccines offer long term protection that's great, but it is still too early to tell.
They might offer long term protection, they might offer more temporary protection, or they might offer some kind of hybrid. Like maybe those w/vaccine can only get a mild infection.
If they only offer temporary protections, getting the whole world vaccinated might be a good more difficult.