In my experience, the CC programs as a whole take longer to load the more infrequently I use them. For example, I use After Effects every day, opening and closing it multiple times, and it loads almost immediately even though I make heavy use of additional scripts, plug-ins, etc. (I am on the 2014 5K iMac).
However, Premiere, which I use less frequently, tends to take quite a bit longer the first time I launch it after having not used it in awhile, but if I close it and then reopen it loads up almost immediately. I've noticed this behavior with other Adobe apps as well (Photoshop, Illustrator, Audition, Media Encoder). For me it may have something to do with the Fusion drive on my iMac, but I can't say for sure.