With the MLB app, you normally get a notification when teams you've subscribed to complete a game. Today a bunch of people got notifications for 50 year old games as if they'd just been completed. One comment in the linked reddit thread noticed that the affected games are some of the most recent games without complete play-by-play information, and speculated that whatever process that send notifications after games are completed only triggers when the complete play-by-play info is added. That triggers for present-day games when they complete, but it also apparently triggers on 50 year old games when their information is updated