Pretty much any virus 'favours authoritarian societies' to the extent that stricter restrictions and their observance reduces transmissibility. And pretty much any society is a lot less likely to worry about movement restrictions being illiberal in an actual war.
This happens to be a virus which focuses most of its harm on elderly people who can be triaged out of care where resources are stretched in conflict situations, causes relatively few issues for combatants and spreads in an unpredictable manner well beyond the target population. Its clearly insufficient to undermine the actual fighting fitness of the societies which make no effort to stop its spread, but at the same time it goes round the world killing random noncombatants and likely gets back to your own population via neutral countries. Clearly far worse as a bioweapon than many naturally occurring viruses, especially when you apparently don't have an antidote and your potential adversaries can develop one faster
This happens to be a virus which focuses most of its harm on elderly people who can be triaged out of care where resources are stretched in conflict situations, causes relatively few issues for combatants and spreads in an unpredictable manner well beyond the target population. Its clearly insufficient to undermine the actual fighting fitness of the societies which make no effort to stop its spread, but at the same time it goes round the world killing random noncombatants and likely gets back to your own population via neutral countries. Clearly far worse as a bioweapon than many naturally occurring viruses, especially when you apparently don't have an antidote and your potential adversaries can develop one faster