I actually find it odd that they don’t require you to supply your own food. Obviously I understand the need for fresh veggies (though again, these should only be ones that you feed), but what if you weren’t feeding oxbow and they just started feeding that? Big no-no. I would be worried that they might give your rabbit something he isn’t used to eating.
What makes you think they are on wire? I couldn’t find anything on the website, but if you have actually seen the place than obviously you would know. 5-6 days could certainly cause problems, and foot abscesses are not easy to treat, though if there was at least a rest area so he could get off the wire that might be okay. Might. It also might be so uncomfortable for him that he won’t eat (enough) depending on where his hay is located.
Could the rescue you adopted him from watch him? March is a lot closer than you think! February is a short month and it will be here in a blink of an eye!