Starting June 8th, Genie+ will no longer be available as a pre-arrival ticket add-on. You'll have to purchase it on the day of your visit, which is now stated as "Subject to availability".
Disney states this is to "Manage the incredibly strong demand our guests have shown for Disney Genie+." But I don't see how this is going to manage things. At the moment, the price isn't changing, so there's no effective price wall to curb everyone from trying to get it. And now having everyone buying Genie+ the day of their visit is gonna' put a strain on WDW's reliably unreliable system. Now with Disney now adding "Subject to availability" to the stipulation, that might mean they'll limit how many people can get it which could help...but with the still cheap price and Disney themselves stating there's an "Incredibly Strong Demand" for Genie+...that's still not going to help things if they do limit how many are given each day.
Now if they later announce dynamic pricing etc. for the day of purchases, then they might be on the right track. But ultimately, they need to curb the demand for Genie+ in order for it to have a chance of working, and a higher price wall is the way to the go.