Will Tokyo 2020 still go on as planned this year?

i think there is no possibility 

As of 4 months ago yes but in the months since it has been cancelled. 

postponed to 2021 :(

which makes sense due to the covid-19 situation

No they are officially postponed to 2021 

A month ago I'd have thought so, but with my country (Canada) on record as saying 'we're not going' I would imagine you will see others follow suit. Best guess is that they push it back a year to 2021.

Almost certainly not with countries announcing that they will not send teams. None of the events used for preparing athletes and selecting teams are being held.

It will be played via PlayStation

I hope not and do not think so.

Because of COVFEFE-19, it won't.