2 Answers
I have submitted your suggestion to the content team for consideration.
It might be worth noting that CF public certs (for content distribution) are sourced from ACM in US East (N. Virginia) only. Certificates used to secure backend traffic to your origins can be sourced from ACM in any region.
…covered by the new Custom SSL Certificates With CloudFront lecture
The new lecture doesn’t cover the issue that the OP made – using the same certificate on ELB and Cloudfront. In fact I would argue the new lecture adds nothing over the content in the previous lecture
The new lecture states ACM works only for us-east-1, but AWS documentation shows that’s not the case:
https://docs.aws.amazon.com/general/latest/gr/rande.html#acm_region