Really? No doctor, but bone breaks heal way way quicker than tendon or ligament tears, I am surprised they're counting him out for the whole year. You are correct in a sense, but broken bones can vary in how they actually broke. A clean break is the best case you can hope for in all situations, or next best is a compound fracture which is multiple clean breaks, then there is the fragmented fractures where the bone has broken in many small pieces kinda like glass shattering. I know about this topic since my brother broke his leg when he was younger and the doctor was knowledgeable and shared the info. All that being said, depending on the type of break he sustained and add in the fact the location is the ankle and requires a lot of functional strength to hold up to the rigors of NFL life, a season gone is not so far fetched. The other half is that he will most likely be healed before the seasons end but then you gotten figure time in to re-strengthen the muscle since he won't be using them for several months. That really does not leave much room for getting back for some game time. The smart approach is to say do not rush back and potentially risk re-injury, as they have so far indicated. There is no pressing need for him to be rushing back either as two others who dealt with similar issues will now be in the running for those reps, Urban and Lewis-Moore who have show play making ability, plus they still have Guy who has been a very solid and dependable player.
You're right, hopefully it is a clean break. Would be great if he could at least get some reps in this year.
I agree its better to break a bone (with area and critical condition considered) than a ligament tear. I played basketball when I had Brown hair and the sprain/ligament damage is a very difficult recovery. The one important factor is he will have the sports specialist doctors.