Yes, very much so.
I don't think that the previous answer is totally correct. The statement posted is valid enough, but it only extends to Jackson's own royalties due to him as a songwriter. It does not cover Lionel Richie's rights as co-writer, nor the record company' publishing rights.
It's not clear whether this legal directive was binding on the 2010 re-release. This notice from USA for Africa shows that some royalties, at least, were still supporting Africa:
Once again, USA for Africa has assembled a stellar line-up of international artists to contribute songs to the project with proceeds from this effort going to assist Africa and Africans with the current challenges facing the continent.
This Chief Executive statement makes it abundantly clear, beyond doubt, that royalties, even if Jackson exempted his own, are still supporting Africa:
“We want to thank you all –individuals, groups, schools, churches, companies – located throughout the world who supported our efforts in 1985/86 and throughout the last 33 years, through the simple action of buying the song, “We Are The World” in all its forms.