You might want to take a more wait and see approach as to whether or not you'll want to keep the crate. If he is already trained to use it, then it is his "safe" place... his "den" if you will. If you had no children (or at least much older children) then it might not make as much difference.. but your new family member may want a place he can go that is "off limits" to the KIDS...
We kept the crate for our German Shepherd for several years - even though she has never been a problem in the house... until I finally was tired of having the big thing in the bedroom. She slept in it often (I covered it with an old sheet and it was like a cave for her), but slowly, over about 2 years in the house we live in now, she started sleeping in the various bedrooms during the night... She makes her rounds to check on the kids and sleeps for awhile in one child's floor, then comes to our bedroom when I go to bed, etc... Just because you don't close the pooch inside, doesn't mean the crate isn't useful. If it is providing comfort for the dog, then it is useful. Ours stopped using hers over a long period of time and is just as comfortable on a bed in a corner of the room. She also naps in the bottom of our bedroom closet (very dark and small space under my husband's shirts) and under or son's bed (when it is cleaned out so she can squeeze under there), and even against the back door in the laundry room (when it is quiet and the light is off). Basically, she discovered her own "caves" around the house and gave up the "crate cave".
I'd get the crate (won't the old owner give you the one he has been using?) and let him use it. It is a fantastic way to teach your little ones to leave the dog alone.... "when he is in his crate you must leave him alone". That way the dog has a place to retreat to when the kids get to be too much for him (or other houseguests.... holiday times can be quite stressful for pets). If he eventually stops using it, then you can decide what to do then.