Firstly, without explicitly permitting bitcoin use for payments, merchants adding bitcoin as a payment method wouldn't happen organically. Without the central bank providing BTC/XAF conversion, it wouldn't be feasible for merchants to add bitcoin as a payment method. With both of those in place, reluctance by merchants is diminished significantly.

Now education will, of course, be needed. But education alone doesn't give a reason to use bitcoin. Almost nobody is going to convert their CFA into bitcoin, only to go and spend bitcoin (at least, not domestically). But if they receive bitcoin, then will then want to spend bitcoin. I gave some examples above on how bitcoin might enter the country.

One important distinction between South Africa and CAR is that all ZAR circulating came at ~zero cost, thanks to seigniorage. With CFA, there is no CFA that come at zero cost, at least not to the central bank serving CAR or anyone else in the country. So there is no direct economic benefit to the government in sticking to CFA (XAF) only. Just as there was no direct economic benefit to El Salvador sticking with the US dollar only.

Also, this law likely isn't about ensuring you can pay in bitcoin for your restaurant meal, but more likely so that the government has access to money that is outside of the banking network (which is dependent on France).

But as you mention -- gotta be realistic. This is not only a very small country (by population) with a civil war underway, but also a country with very few resources to address the many needs of its people. But I don't think making it explicitly legal to own and use bitcoin in commerce is a bad first step.