So far, the "only" Arab countries to confirm attendance are the hosts from Bahrain, the UAE, Saudi Arabia - and Qatar.
Just getting the Gulf countries and Qatar together in the same room is a pretty big deal. Qatar's ties to Iran have caused most other Arab countries to sever diplomatic relations with it in 2017.
This conference would be newsworthy just for that.
Qatar's attendance makes sense because it already works with Israel to provide aid to Gaza, when the other Arab nations have given up on or are against such aid that may help Hamas.
Add Israel to the mix and even if nothing gets accomplished because of Palestinian intransigence, it is a huge diplomatic win for Israel and the US in bringing cooperation between the countries.
If Obama would have managed to do this, the praise for his brilliance at diplomacy would be dominating the news coverage. But since it is Trump, the conference is being dumped on as a massive failure by the media.
One does not need to be a fan of Trump to realize what incredible double standards are at play here.