Could be good if they are willing to try, and you choose a distro that closely resembles Windows. And they aren't purchasing new hardware and their current Windows OS isn't being supported anymore.

Big fan of if it works, why change it?

Also, don't promise them that it'll be perfect and magical, set their expectations to be realistic. (This is where typically people convinced to buy a Mac quickly learn to hate it. They are promised it will never have problems and then they have one problem after another, leading to hating it and tired of having to message for more help. And a lot of people I've found that sing blind praises for anything are the same ones quick to blame and down talk users when things goes wrong)