Just to make sure I've got this right: You put yourself on the waitlist for a sold out Egypt departure, which goes exactly when you want, and you just found out you got in? But now you're not sure you want to go? Or are you just gun shy to put down a deposit because it's been cancelled in the past? I get that; I've had
ABD departures cancelled on me, and I lost money on the most recent cancellation. And honestly, it just spoiled the whole anticipation for me, and I have not ever sign up for either of the cancelled departures (even though, in both cases, the alternate trip I ended up taking was better than the one I'd signed up for originally). But honestly, if it's actually your dream trip and dream time period, I say go for it. If you don't put the deposit down, I'm assuming they'll offer the spot to someone else. You might end up regretting not doing it. Are you worried about the war going on in Israel/Gaza?
I'm also curious how you ended up losing the money. Was it airfare? OYO activities you'd booked? I lost money from both of those when my Portugal ABD was cancelled.