From what I read on the ESO sub-reddit, I quote the following by Chromozon:

''I played ESO for 6 months on a hard disk. I then copied it over to an SSD and have been using that since.
I saw no difference moving ESO from a hard disk to a really good SSD. Game load time was the same. Loading screen time was the same. FPS stayed the same.''

Apparently because ESO is an MMO, heavily focused on your internet connection like any ordinary MMO. SSD/SSHD would improve loading times on single player games but not on MMO's. Hope it helps.

Thanks for the responses. I did see were IGN did a test in like June and certain games it did cut the load times in half. GTA was the biggest difference . Would like to hear directly from Zen if they had any info. I'm due for a upgrade anyways on my ps4