Is hiring without a 'remote possible' option discriminatory?
There are many people that cannot in the foreseeable future be in a public space (i.e. an office), because they're in high-risk categories for COVID-19. For example, immunocompromised people, pregnant females, etc. But also there are others who are just not comfortable with the possibility of contracting the virus, irrespective of their risk group. At least not before a provenly working vaccine is available.
In this light, is it a discriminatory hiring policy (maybe not according to local laws, but in the broader sense) when a company requires in-office presence for their candidates?
Yes, it is discriminatory. But discrimination isn't illegal; discrimination against protected classes is. Examples of things hiring personnel can discriminate based on include political views, your weight, your sexuality (at leas here Texas), credit history, any bankruptcies, and unemployment.
I think so, except when it’s a position that does actually require one to be in a lab or manufacturing plant or similar. It will take a lawsuit to actually establish this but I imagine a law firm would take a case like this on contingency against a big company.
Likely so.
Also once there is a coronavirus vaccine, it will likely be considered discriminatory to require vaccination as a condition of employment in order to enter a company office.