Unlike the other payments like OTB, HST, CCB etc - My Account in CRA doesn't show the OAS and GIS payments, so you can't even check if the extra $300 or $500 one time payment is coming or not.
I guess you just have to trust Trudeau on that one, I guess.
I didn't think My Service Canada account shows that extra one time covid payment. They probably just show the regular OAS, GIS and CPP payments, and the extra $500/$300 might not show up.
So you just have to hope & pray it comes in, because Trudeau said so!