You were the new kid on the block, the one most likely to be forced, if the company has to go that route, so yes calling and checking was a good thing to do. I would expect most companies to avoid lawsuits later down the road will work on a First-In last-out basis when it comes to needing to forcibly furlough people.
So expressing your concerns for the situation and trying to get and stay informed may have a beneficial effect later down the road for you.
Yeah that's a good point, it makes sense they would opt for FIFO(or furloughed) if they had to add to the tally of people who'd volunteered.
The boss is a decent chap, and hopefully being pragmatic about it has shone through the 'this lazy bugger, only just started here as well!' vibe :)