So that table you linked (and I can't read) clearly state that if:
Home not principal workplace but has dedicated work area, then you can't claim occupancy expenses (rent/mortgage).
My question then still stands: if you have to work from home for the next 3-6 months, where the fuck is your principal workplace?
I think the ATO would change it if they would like to avoid processing an influx of home office expenses. The current crisis is forcing lots of people to work from home, for the foreseeable future.
And I'm arguing for people to claim it because I have done so over last 20 years, both as an employee with a sporadically used home office (excluding rent), and as a business owner as a principal place of business (including rent).