I really don't know what you mean byWhat happens to my account?
...
You are still a current member, and have the ability to download any of the current templates.
If a version of the template you want is not available, well then, it's not available.
The differences between J1.0 and J1.5, and J1.6 are miles apart.
They are not upgrades, they are entirely different templates.
If you read the comments from the link I provided, it's easy to see that even if you had a J1.6 version of the template, there is no way to migrate from your current site, which means you would have to start your site from scratch, cutting and pasting from the old site to the new one.
IMHO, I would wait for a version of Joomla that would allow me to migrate from an old site to a new one.
Anyway, please look at the thread I provided a link to, and the links to additional information.