The style of the end titles is very similar to the opening titles which feature lots of the deaths from the earlier movies. So some people reckon that showing the earlier movie deaths and then finishing up in a similar style is supposed to show that this film represents the whole series and is bringing closure to it. Personally I think they can just bolt any number of these films in to the series now, this one doesn't have any links to the earlier films other than the aforementioned opening titles and at one point they mention "we googled for people that were supposed to die" or something like that and show a pile of google print outs that I think included the earlier casts, but there's no further linkage, it's not like FD2 where they go find the girl from FD1.
I am sure it mentioned the survivors of flight 180 in the google print out
was that not the flight number of the original plane explosion in the original
not sure I saw reference to the highway pile up or rollercoaster survivors, but it went by so quick, could have missed it