In answer to your question, no, it is not resolved. When I left Guernsey after my last visit being unable to connect, I spent half an hour on the phone in the UK, where I live, to Virgin customer care who don't know anything about the SIM Toolkit or why/how I could not connect without it. Despite checking with supervisors etc. They checked all the standard things on my account such as roaming, etc.
The only thing they insisted I do is change my SIM card to a brand new Virgin SIM (they said they could not move me over to O2 and send me an O2 one). I maintained that a brand new Virgin SIM is not going to be the solution unless the SIM Toolkit can be accessed. They nonetheless want me to try this and have given me a new one. I return to Guernsey this coming weekend and they have promised to call me when I return to find out if it worked.
I imagine we will simply remain unable to access any Guernsey networks until such time (which they are unable to tell me) as we are moved to O2. If I can't access Guernsey networks this coming weekend, I will leave Virgin.