Anyone know how Windows 11 will work with our CAC readers, especially since it's going to push MS Edge over Chrome and IE?

I completely understand your hesitation about updating to Windows 11, especially if CAC reader compatibility is a concern. It's crucial to ensure that all your essential tools and applications work seamlessly.
Windows 11's shift toward promoting Microsoft Edge is indeed a notable change. If you're unsure about how it will affect your CAC reader or if it will prioritize Edge over Chrome and IE, you might want to explore https://learnmesccm.com/ . They cover various tech-related topics and might have insights or solutions to address your specific concern.
Taking the time to research and gather information before making a significant software update is always a wise move.

Not knowing your specific set-up it would be out of line for anyone to suggest any hard and fast solutions to you. However, I am currently WFH 60% and in the office 40% of the work week (Contract instructor supporting USAF cyber training) and we use DoD Teams via Edge as our primary communications method and I have access to my .mil e-mail and SharePoint. As the current version of Edge is using at least some of the chrome code-base, you should be ok. I would try loading Windows 11 up as a virtual machine, adding the root certificates and giving it a go. Not knowing your technical ability, you might consider grabbing your local computer nerd to assist in setting it up.

Edit to add: This is what I plan on doing in the near future

From what I understand of the rollout Windows 11, MS Edge will have to offer an IE compatibility package as they go to phase out IE. So this shouldn't be an isssue, but it's possible to acquire Windows 11 and try it out on a home computer with a personal CAC reader of your own, just have a backup Windows 10 OS bootable media to revert. Obviously you could lose saved files on the PC you try this on, but you could always backup the media on that PC with an external drive then proceed.