After years with “missed schedule” posts on (paid!) wordpress.com based sites, WordPress has documented that the scheduler officially does not support more than 100 posts:
[WayBack] Warning: Please do not schedule more than 100 posts. Any posts scheduled beyond that amount will not be published.
In practice this is not fully true, so lets explain that a little.
Background
Imagine the list of scheduled posts as a list of posts to be posted anywhere from the near future (lets call that tail) until far in the future (for now head).
As long as you schedule posts in head to tail order, then there is no problem. You can schedule 100s of posts (usually I’ve between 700 and 1200 posts scheduled that way).
The problems appear when:
