Just received the same email and was able to change my award flights from February to May (also to Israel). No issues with the request. Took about 10 minutes and received the confirmation email with the new flights. I would suggest calling again to speak with someone else.
Thanks. I tried again and they were still confused about the policy! I guess I'll keep trying. Sigh.
EDIT: Fifth time calling was the charm! I got a rep who changed it all. Not sure if it helped, but when I dialed 800-772-4642 I asked for Avios reservations. The nice thing about the change is I now get good weather in Spain and Israel. Fingers crossed the world is sufficiently back to normal that we can take this trip. Truly, nobody knows yet.