Today I got a brand new computer for work and I am ecstatic to report it is a beefed up, brand new 2015 13″ Macbook Pro. I love it right away (of course) but quickly realized the new Force Touch trackpad did not have three-finger drag as a default option. I didn’t find the drag setting anywhere in the trackpad options (in System Preferences), but luckily I found a support thread that helped me out.
System Preferences > Accessibility > Mouse & Trackpad > Trackpad Options > Enable dragging (click checkbox) > three finger drag
Hard to find location, but SO HAPPY the functionality is still available.