Linden Lab announced a few hours ago that Gachas will no longer be permitted from midnight SLT on August 31st.
Here is the full official announcement;

Due to a changing regulatory climate, we’ve had to make the difficult decision to sunset a very popular sales mechanism for content in Second Life.  It’s widely known as “gacha”, and is defined by a chance-based outcome as a result of a payment.  
We know that creators plan their content releases far in advance and will need to re-tool their products, so to mitigate the impact to those affected, we are giving a 30-day grace period, until midnight SLT on August 31.  After that time, selling content via gacha machines will no longer be permitted in Second Life.  Enforcement won’t start until September 1; after that date an Abuse Report for “Gaming Policy Violation” will be the preferred method of reporting this content to Linden Lab.  
We will continue to allow any sales where a payment is given for a known item, which means that items that had been purchased as “gacha” will be allowed to be re-sold as long as the buyer knows in advance the item and quantity they will receive. We will, of course, still allow fatpacks, and any other currently-allowed distribution mechanisms. 
We did not make this decision lightly and we understand that it will impact creators as well as event organizers and certainly the shoppers! We look forward to fun creative ways of engagement that will come instead.  
We realize that this announcement may leave the community with questions.  This forum thread is going to be monitored and we will answer any related questions in there. 

I freely admit that I did not like the Gacha system, I often was frustrated by them, simply wanting to buy something to find that I had to spend ages playing to get what I needed, ending up with lots of stuff I didn’t want, etc.
But they are a huge part of Second Life and big business.