You couldn’t be harassed for being Jewish since unless you carry and Israeli passport there is no indication of one’s religion on a US passport. Your argument is invalid UNLESS you have multiple Israel stamps of entry in your passport. You cannot get into Egypt if you have Israeli stamps (from personal experience). In the 80s I had a hard time getting into France with legitimate visa, current passport, lots of documentation for a one week work destination (doing field service), and loops prior recent trips to Israel.
You do not know what you are talking about
I do have multiple Israeli stamps in my passport; also I know a lot of people who are Israelis who fly to the UK regularly (even weekly) without incident. This story makes little sense. But don’t let that from trusting some random newspaper in Kansas City over basic common sense.
“You cannot get into Egypt if you have Israeli stamps (from personal experience).”
Nonsense. I know many who have done just that. And, there is a border crossing between Israel and Egypt (the Taba crossing, down by Eilat), so travel to Israel is clearly not a bar to travel to Egypt.