Did they say they would cover the cost of fine-tuning again? I saw them say they would cover the cost of recalculating embeddings, but I didn't see the bit about fine-tuning costs.
On fine-tuning:
> We will be providing support to users who previously fine-tuned models to make this transition as smooth as possible.
On embeddings:
> We will cover the financial cost of users re-embedding content with these new models.
This indicates to me that some of the old base models used architectures that were significantly more difficult to run at scale (or to ship around/load different weights at scale) - which is truly saying something, since they were running at incredible scale a year ago. There's probably a decade of potential papers from their optimizations alone (to say nothing of their devops innovations) that are still trade secrets.
On fine-tuning:
> We will be providing support to users who previously fine-tuned models to make this transition as smooth as possible.
On embeddings:
> We will cover the financial cost of users re-embedding content with these new models.