I'm a fan of Fight Pass, but I sense I'm the exception to the rule. There is one substantial problem with the timing.
I think getting people to pay for something when it was offered for free is a major flaw. I for one loved watching prelims on YouTube live streaming. That apparently is replaced with Fight Pass access only. It does appear that the "free" access to many lesser events will become the content for UFC Fight Pass.
Go ahead and check the UFC and upcoming events. What you're going to see a whole lot of "exclusively on Fight Pass". That means for a lot of people, no free fights that you enjoyed for quite some time.
Paying for a subscription to see fights that you once enjoyed for free is a true test. It's a test of your dedication to the UFC and MMA. I for one will subscribe but I'm likely to be the exception.
Have you tried to watch prelims on YouTube/Facebook only to be disappointed lately? Did the UFC win you over to the point that you will pay to get those fights that you once watched for free?
If you're not clear on the Fight Pass integration, do yourself a favor and see the UFC homepage and look at where to watch.