There are certainly problems with teaching it as a second language, but it’s still taught by UNRWA teachers (to at least one third of the kids there) from an early age.
I grew up in Jordan and the average young person will in most cases speak good English. It fades with older generations given how much their education sucked, but a large portion of people speak it. I’ve even been told that it was taught better in the 80’s than now.
Don’t think I’ve ever met anyone who doesn’t speak enough English to communicate with someone on the street except for my Grandma and she was basically illiterate.
What country are you from?
Ps: to answer the question specifically about Gaza, I don’t have any stats for that, but I know the UNRWA schools teach English