You won't see new posts on Beehaw communities from other instances where Beehaw has defederated from. So lemmy.world users won't see new posts or comments on Beehaw communities, nor will Beehaw users see anything new from their communities.
Think of defederating like turning off post/comment syncing between instances.
You can do all these in Maps (minus toll passes). I'm not sure how an ETA could be personalized (I don't use Waze) but Maps is pretty accurate with ETAs as is.