I have bought used laptops (not from an official program like Dell Refurbished, though)— I would advise not to care what operating systems or drivers may or may not be on it, unless that is part of the deal, since you will be installing your own anyway.
I have also decommissioned machines, in which case the storage drives were securely wiped, meaning there should be nothing on them.
If you are installing Windows, a lot of drivers are available via Windows Update, so it is not always necessary to find each and every one on the manufacturer’s web site.
Recently, my cat knocked over a mug of water and shorted out my gaming laptop, and i discovered that the extended warranty I’d bought (and regretted) was still in force. Dell replaced the hard drive, installed a vanilla Windows, and then gave me extremely explicit instructions on how to download and install a handful of other needed drivers. I don’t remember why, but the second step was over the phone. And i think they offered to send someone back to finish the job, but it would have taken days, and i could do it myself in an hour.
I’m hunting too (refurb 14" Win laptop) and keep an eye on slickdeals for short notice bargains. It has its share of iffy sponsored listings and notsogreat buys but the userbase is quite chatty and quick to point out gotchas in the comments. They’re also remarkably longlived, for a messageboard. Lots of 10yo+ usernames, second only to this old place.