I am thinking that the fixture and season could be easily disrupted. Look at current Sydney siruation. Say this occurred under thre months away. Neither Sydney team could leave NSW, no Vic team could play there and return without quarantine. Look at impact on Sydney Test, even Warners availability for Melb if fit. Gabba test who knows.
When we were in a virtual national lockdown hubs could be arranged (eventually) but sporadic outbreaks combined with knee jerk border closures are a major threat to 2021 season