16:49 UTC refers to when TMZ first reported Prince died. Prior to that, there had been plenty of reports that there were ambulances at Paisley Park. It is not strange that people would google either "paisley park" or "prince" and then follow the results to Prince's wiki page.
I don't know the exact timeline, but my understanding is that there were reports of a death in the area where Prince lived before it was known that it was Prince.
I found a few references to stories about a 'medical situation' at Paisley Park that came out before TMZ's report—I'm assuming it was those reports.
I wonder if there's a crossover between celebrity reporters, and people who update Wikipedia on celebrities?
I'm seeing an exponential curve, isn't it what we should expect ?
Look very closely at the section of the graph starting around 4:20 PM. There's a small but significant increase in hits before the big spike starts around 4:50.