I've never heard of the name
Poppy being used in an English speaking country? The only person I can think of is
Poppy Montgomery, an actress. I also call my dad
Poppy so I don't think it could ever be usable for me. lol
I think it's usable for other people and it probably wouldn't get mispronounced in the U.S. It's okay but I don't know if it'll age well.