There are so many "ifs" still relevant.
If no new variants emerge that reduce vaccine effectiveness.
If there isn't a winter upsurge from October.
If the vaccines keep virtually everyone out of hospital.
If the vaccine uptake in younger age groups is high enough to put a lid on infections.
If we are all sensible when restrictions are lifted and the R" and "K" rates don't spike.
If the lockdowns haven't changed people's behaviour to the extent that they won't go to large indoor events.
If traders still exist and are wiling to commit.
It is, I think, too early to know enough answers to make public announcements.
I do feel great sympathy for the organisers who must put in a lot of work that cannot be left until later and might, again, see it all wasted. Do they have the courage, and financial backing, to keep trying?