Crabgrass seeds can lay dormant in the ground for many years. I have Bermuda at one of my properties and I always applied a pre-emergent but I forgot this year. The Bermuda is infested with crabgrass now.
I ran a dingo cultivator over a property last year and seeded with Zenith Zoysia. Prior, it never had a weed of any type. Within a week, the entire area had a crabgrass seedling at least every square inch. Luckily, Zoysia is great at crowding out weeds and it's weed free this year.