Both are indeed correct: you must now provide a credit card to use Cloud Functions, and you do get a free tier on the Blaze plan.

In fact, the Blaze plan comes with a free tier that is bigger than the limit of the free plan was, but you can no longer use it without entering a credit card.

This change came while adding support for newer node.js versions. Cloud Functions now uses Cloud Build to create its containers, and while Cloud Build does offer a free tier, you'll have to enter a credit card to use it.