Looks like their own HF link is broken or the collection hasn't been made public yet. The 14B instruct model is here:
https://huggingface.co/mistralai/Ministral-3-14B-Instruct-25...
The unsloth quants are here:
https://huggingface.co/unsloth/Ministral-3-14B-Instruct-2512...