Eamon, back on October 7, we consolidated AI providers under "Use AI".
https://www.clay.com/changelog
I've tested a few times, and when I create a new table from template with an AI column, the new table use the AI provider I set in the template.
Ditto when I save the column as a template – my chosen provider stays in place.
Are you seeing different? I'd love to have a look at an example table where this is happening in your account.