The cards are produced months in advance. It would be impossible to have accurate checklists for any release prior to January of the following season. People seem to think that manufacturing a card set takes a just few days...
I think the January estimate is a bit off base.
Using the example of Topps Match Attax in the Bundesliga, you see a roster based product that is way more accurate than Upper Deck hockey releases. Released about a month into the season. Of course, Topps' hand is forced, as there is always two newly promoted teams, and new shirt sponsors to consider.
For the record, Topps MLS products are horrible. So it's not the company, it's the unique situation of promotion/relegation in European soccer.
Upper Deck's lead times have always been huge, so this is nothing new. Since these two sets (MVP, OPC) have no longer have any serious auto/game-used content, and are basically direct from image design to printer products, they have the opportunity to make a positive change. Relevance matters when trying to reach what I would call the "team set" customer base. The marquee signing of this past season, John Tavares (signed 01 July 2018) could have easily been updated before heading to the printers.
My favorite example a great effort of days gone... Ray Bourque was traded to Colorado on 03 March 2000... Pacific had a
game-used jersey card of him in 2000-01 Pacific (released in the Summer of 2000).