Cycling gets you away from common transmission vectors such as handrails on public transport and breathing in coughs and sneezes.
The daily dose of excercise in cold fresh air seems to strengthen the immune system.
Was thinking just the same as your first point.. granted everyone's circumstances are different; however regardless of whether it's your chosen form of recreation or necessary transport cycling is going to get you out in the open and away from others (a compelling argument even without the slim threat of death thrown in!).
From the perspective of alternative transport, on the road you're away from densely-packed pavements, busses, trains.. cars if you would otherwise be travelling with one or more passengers. Alternatively if you're a only a recreational rider, you're still likely to be better off than if your alternative choice of sport or hobby involved being indoors / around others.
Also stands to reason that if you're a regular cyclist you're likely to be more healthy and resistant to infection. The flip side I suppose is that this might go the other way if you're in the habit of exhausting yourself or maybe get caught out in the cold / rain..
Common sense says to avoid all possible sources of exposure in the event of a widespread outbreak (which may or may not happen) and I think cycling would certainly help in this regard to some extent.