Rents can only soften on new leases signed, any short term falls...

Rents can only soften on new leases signed, any short term falls in rentals will therefore be minimal to income generated next year.
For there to be a material impact on income the rental falls from the current contracted level would have to be protracted
i.e based an a long term event (long recession) or a fundamental change to working practices.
Like you I don't buy the working from home paradigm.

4.3% of properties are currently vacant (with an insignificant amount in VIC/NSW) & 10.2% up for renewal in FY21.
Even if there was an across the board fall of 10% in rental rates, which there hasn't been, that would mean a 1.4% drop in income / distributions.
That would drop the yield from a current 8.5% to 8.3%.

IMO the market has priced in something that isn't going to happen.