It would have been gauche for them to release a signed statement of his stepdown if he was actually dead, but if he's actually in bad enough condition that he can't appear in public for the forseeable future, it makes sense that they'd want Kamala in as soon as possible to take over the campaign.
Second Cup is just a second rate Starbucks in Canada, and the one she owned just happens to be located in a Jewish hopsital, so unless more information comes out about the situation, it's sort of impossible to say.