So strange since these are the same level 10 instances you should've already had access to, no wonder you're frustrated!
To see if anything had changed, I just went to Chromie on a level 15, chose the "Portal To Outland" option ... specific dungeon queue now shows me 8 options, the four you mention plus Auchenai Crypts, Mana-Tombs, Sethekk Halls and Escape From Durnholde.
Changing the timeline to "The Cataclysm" I get 22 specific options it looks like, 8 of them for 15+.
Wait that's alliance, just going to check Horde on the off-chance faction affects it.
Nope, same list of dungeons from Chromie in Org, damn.
As far as I know you should have access to all the same options as me ... but apparently Chromie isn't showing you all these ... my apologies, I can only guess there are differing levels of Chromie access depending on account type or sub or something?