How did Deadpool know about Logan?

I’ve been thinking of the timeline after reading an article from itechpost that also matches with the data on https://mcu.earth616.org.

It states the order of how Deadpool 2 and Logan plays out together in chronological order. This said, it’s been quite a mission to complete the “occuring movie years” for the X-men Legacy since Fox practically destroyed the timelines with reboots and such – and I’m much aware of the fact that Deadpool 2 occurs long before Logan.

I’m of course also aware of the default 4th walling here and that Deadpool might know about those events due to this. And I guess that there has been quite a time traveling, according to the post credit scenes since then. But shouldn’t this occur in some kind of reverse order? If Deadpool 2 begins with a “Death of Logan” reference, and ends with Deadpool time traveling – how could he possibly know?