No. ACM has been on a slow path towards making everything Open Access for many years now - driven both by internal and external feedback. Given that the ACM Digital Library (individual and library subscriptions) has been subsidizing other ACM endeavors, that making stuff OA is not something you can take back later, and that the required article processing charges (APCs) cause other problems, they have been rather careful with the transition.

They plan to make the entire digital library freely accessible by January 1, 2026.

Here's a short article about timeline and implications: https://medium.com/sigchi/about-acm-open-cd544408559c

EDIT: for anyone wondering why there need to be APCs at all, Jonathan Aldrich gives a glimpse into costs and benefits of 'traditional' publishers: https://medium.com/sigchi/what-benefits-do-traditional-publi...