By most accounts there aren’t any surviving prints of the film with the epilogue intact. What little has survived is not enough for a full restoration. This is why the epilogue is only shown in brief clips in the documentary on the DVD/BD.
In fact it was actually a miracle that the flower girl scene from Frankenstein was found fully intact, considering it was cut from the negative and destroyed soon after
What was used in the current restoration was from some print in the UK that happened to have it, it has noticeably worse quality than the rest of the movie and you can even see the quality shift in the next scene after it cuts back to the lower generation footage (idk what element they used for the rest of the movie)