Peter Calver from Lost Cousins has helpfully pointed out that Findmypast last week added an index to UK deaths in this period which covers about 2.5 million deaths, which is about 50% of all deaths in that period.
He found his father's death in 2011 but with errors in the index.
My father who died in 2007 is not listed.
So the message is, it might help, but just because you don't find someone does not mean that they are not dead.