Well, wouldn't ya know it, it seems it can happen in some parts of the world, but not others.
If you live in NY USA you might be safe, Just2 b. Unfortunately I do not live in NY USA, and it CAN happen where I am! Drat.

Case in point - after several years of therapy and working on developing coconsciousness I returned to my family of origin, and lost all contact with my insiders for several years. Internally it was silent to me, and I believed they were not there at all.
It was only several years later when I moved away from my abusers again that my insiders and I reestablished contact again. I found out they had been quite active during those years, but I was completely amnesiac about it.

So yes - I am absolutely sure that you can lose coconsciousness with alters after coconsciousness has been established. At least in some parts of the world ... what happens in NY, USA is out of my jurisdiction.