A lot of Force Majeure definitions I see specifically include pandemics as a force majeure event so I would be surprised if they didn't either.
To add to that, most FM Event clauses allow early termination but only after a set period (3/6 months is usually typical in the contracts I see) so we could see sponsorships etc end early, but not for another couple of months if we have no football.
Regarding extensions of contracts etc, this will depend ultimately on what the parties agree (and, if our club has been proactive and got a replacement sponsor etc, they will also need to ensure it doesn't cut across anything that contract says).