Here’s another article on the subject, just posted by Newsweek.
It looks like Trump’s still planning to attend, based on the Newsweek article. I would imagine the event could still proceed, as long as the fundraising aspect of it isn’t being advertised. What’s to stop Witkoff from inviting a few “friends” to his suite? And who’s to stop those friends from donating to Trump if they want to? I suspect the fundraising event will still go as planned - just unofficially.