I would hold off because I don't know if this will be retroactive when they do fix it. You might consider filing a ticket to see if there's anything a UA can do about confirming/marking how many you have deleted in case it isn't retroactive and they are able to award it manually. No idea if they really can do anything.. but it doesn't hurt to ask.

The pumpkin deleter achievement is only active during morostide. Any you delete now won't count.

I know, but I am just letting you know that if you deleted any after morostide (when you posted on 11/10) that they would not count. Did you make a ticket like the others in the topic?