I don’t think it’s so much that people expect GRRM to die soon – nevermind the fact that he’s well into his 70s and rumors about his health are irrepressible – as it is that the most recent book in the series was released thirteen years ago.
Between the first two books, there were two years, then another two years for book 3, then five years, then six. It’s simply a matter of an unfavorable mathematical progression. Even if by some miracle he drops Winds of Winter tomorrow, the planned final book would seemingly take at least as long again to finish, and given the difficulty of endings, probably much longer than that. GRRM could live to 100 and we would be lucky to see him complete this series.
“Soon” doesn’t even come into it.
It is fenced off on the grounds of the Royal Hospital in Chelsea, but some good aim with a small catapult could still get the job done.