Alex especially has been doing music with other musicians recently. I keep seeing articles showing up on a Rush-fan Facebook group I belong to.
Geddy has been traveling around everywhere promoting his
Bass book. Fans have been talking about how friendly he has been in the meet and greets. Interesting to note that he never mentioned anything about Neil's declining health in these events.
As for retiring, this is something that is in their blood. They will likely never do anything related to Rush again, but I do see them making music with others and maybe with each other, just not Rush.