Yeah, so let's talk about that. If 1492 is the correct date, and Elturel both descended into Avernus and is now back, which is stated in the game by multiple sources of books and logs, then Kreeg's deal with Zariel fifty years earlier would mean that Kreeg made his deal at least in 1443. However, almost every timeline I find says 1444 is when the events of the vampire High Rider occur and the deal is made with Zariel to create the Companion.
So are we changing timelines? Did the events of the Companion's appearance happen in 1442 or 1443 (1443 would only make sense if you count both 1443 and 1492 as part of the 50 years)?
See, these little details are just not adding up.
This seems to be a general problem that the WotC has with dates.