to put your mind at ease, I had done Ft Wilderness campsite reservations to get 60 days FP+ those additionnal visits were to take place 10 days ago
Change of plans, I had to cancel the reservation that sported the 60 days FP+
I had this email, and didn't take much notice, since we weren't doing disney on that day
as the email said our FP+ would drop off if I didn't link a ticket or a hotel reservation, I didn't cancel the FP+, thought disney would do it for me (lazy me, lol)
on the morning of our visit, some 2.5 weeks after I cancelled the "hotel" reservation, lo and behold, the FP+ were still there
so, no need to get out of your meeting or call 911 ...
... your FP+ won't disappear in the next couple of minutes
call disney when you have time to (and expect very long waits on the phone, as Dorian has loads of people call disney to make amendments