For the time being, I would celebrate on par with what's usually done.
I wonder if, because he usually takes care of these things, he's worried that no one will step up when it's his turn (I've seen it happen). Going forward, I suggest having someone split birthday duties with him. Divide up the list - alphabetically, alternate months, whatever - the point is James and his "partner" would cover each others birthdays.
I'm wondering if this is it.
Every once in a while we have a birthday thread on here where someone is upset their SO didn't do the right thing for their birthday. Inevitably people will ask "well did you
tell them you really wanted a cake/to go out/to have a quiet night in/to get a gift/to not get a gift? They can't read your mind, if you want something, even as simple as a cake, you need to communicate that clearly and directly."
Perhaps in the past James has orchestrated birthday treats for others and then when his birthday rolls around you can hear crickets chirping as absolutely nothing was done for him. Let me tell you that feeling
hurts. So maybe he got the advice to be very clear - don't hint, don't assume people will know that just because he does for others he'd like stuff done for him, etc, and he's just going about it awkwardly.